DATA PROCESSING SYSTEMS INCLUDING OPTICAL COMMUNICATION MODULES

[0001] This is a continuation-in-part application of PCT application PCT/US2021/022730, filed on Mar. 17, 2021, and PCT application PCT/US2021/035179, filed on Jun. 1, 2021, and claims priority to U.S. Provisional Application 63/080,528, filed on Sep. 18, 2020, U.S. Provisional Application 63/210,437, filed on Jun. 14, 2021, U.S. provisional patent application 63/088,914, filed on Oct. 7, 2020, U.S. provisional patent application 63/245,005, filed on Sep. 16, 2021, U.S. provisional patent application 63/116,660, filed on Nov. 20, 2020, U.S. provisional patent application 63/146,421, filed on Feb. 5, 2021, U.S. provisional patent application 63/145,368, filed on Feb. 3, 2021, U.S. provisional patent application 63/159,768, filed on Mar. 11, 2021, U.S. provisional patent application 63/225,779, filed on Jul. 26, 2021, U.S. provisional patent application 63/175,021, filed on Apr. 14, 2021, U.S. provisional patent application 63/208,759, filed on Jun. 9, 2021, U.S. provisional patent application 63/173,253, filed on Apr. 9, 2021, U.S. provisional patent application 63/245,011, filed on Sep. 16, 2021, U.S. provisional patent application 63/178,501, filed on Apr. 22, 2021, U.S. provisional patent application 63/192,852, filed on May 25, 2021, and U.S. provisional patent application 63/223,685, filed on Jul. 20, 2021. The entire disclosures of the above applications are hereby incorporated by reference.

[0002] This document describes data processing systems that include optical communication modules.

[0003] This section introduces aspects that can help facilitate a better understanding of the disclosure. Accordingly, the statements of this section are to be read in this light and are not to be understood as admissions about what is in the prior art or what is not in the prior art.

[0004] As the input/output (I/O) capacities of electronic processing chips increase, electrical signals may not provide sufficient input/output capacity across the limited size of a practically viable electronic chip package. For example, some data centers include racks of data processing servers (e.g., switch servers) and use optical fibers to transmit optical signals between the data processing servers. Each data processing server receives first optical signals from optical fiber cables, converts the first optical signals to first electrical signals, perform operations (e.g., switching operations) on the first electrical signals to generate second electrical signals, convert the second electrical signals to second optical signals, and outputs the second optical signals through the optical fiber cables. For example, each data processing server includes a motherboard installed horizontally inside a housing, with a data processing integrated circuit mounted on the motherboard.

[0005] In a general aspect, an apparatus that includes an optical interconnect module is provided. The optical interconnect module includes: an optical input port configured to receive a plurality of channels of first optical signals; a photonic integrated circuit configured to generate a plurality of first serial electrical signals based on the received optical signals, in which each first serial electrical signal is generated based on one of the channels of first optical signals; a first serializers/deserializers module comprising multiple serializer units and deserializer units, in which the first serializers/deserializers module is configured to generate a plurality of sets of first parallel electrical signals based on the plurality of first serial electrical signals, and condition the electrical signals, in which each set of first parallel electrical signals is generated based on a corresponding first serial electrical signal; and a second serializers/deserializers module comprising multiple serializer units and deserializer units, in which the second serializers/deserializers module is configured to generate a plurality of second serial electrical signals based on the plurality of sets of first parallel electrical signals, in which each second serial electrical signal is generated based on a corresponding set of first parallel electrical signals.

[0006] In another general aspect, an apparatus that includes an optical interconnect module is provided. The optical interconnect module includes an optical interconnect module, which includes an optical input port configured to receive an optical signal; a photonic integrated circuit configured to generate a first serial electrical signal based on the received optical signal; a first serializer/deserializer configured to generate a set of first parallel electrical signals based on the first serial electrical signals, and condition the electrical signals; and a second serializer/deserializer configured to generate a second serial electrical signal based on the set of first parallel electrical signals.

[0007] In another general aspect, an apparatus that includes an optical interconnect module is provided. The optical interconnect module includes: an optical input port configured to receive a plurality of channels of optical signals; a photonic integrated circuit configured to process the optical signals and generate a plurality of first serial electrical signals, in which each first serial electrical signal is generated based on one of the channels of optical signals; a first deserializer configured to convert the plurality of first serial electrical signals to a plurality of sets of first parallel electrical signals, and condition the electrical signals, in which each first serial electrical signal to converted to a corresponding set of first parallel electrical signals; and a first serializer configured to convert the plurality of sets of first parallel electrical signals to a plurality of second serial electrical signals, in which each set of first parallel electrical signals is converted to a corresponding second serial electrical signal.

[0008] In another general aspect, an apparatus that includes an optical interconnect module is provided. The optical interconnect module includes: an optical input port configured to receive an optical signal; a photonic integrated circuit configured to generate a first serial electrical signal based on the received optical signal; a first deserializer configured to generate a set of first parallel electrical signals based on the first serial electrical signals, and condition the electrical signals; and a first serializer configured to generate a second serial electrical signal based on the set of first parallel electrical signals.

[0009] In another general aspect, an apparatus that includes an optical interconnect module is provided. The optical interconnect module includes: a first deserializer configured to receive a plurality of first serial electrical signals, and generate a plurality of sets of first parallel electrical signals based on the plurality of first serial electrical signals, in which each set of first parallel electrical signal is generated based on a corresponding first serial electrical signal; a first serializer configured to generate a plurality of second serial electrical signals based on the plurality of sets of first parallel signals, in which each second serial electrical signal is generated based on a corresponding set of first parallel electrical signals; a photonic integrated circuit configured to generate a plurality of channels of optical signals based on the plurality of second serial electrical signals; and an optical output port configured to output the plurality of channels of optical signals.

[0010] In another general aspect, an apparatus that includes an optical interconnect module is provided. The optical interconnect module includes: a first circuit board having a length, a width, and a thickness, in which the length is at least twice the thickness, and the width is at least twice the thickness, the first circuit board has a first surface defined by the length and the width; an optical input port configured to receive a plurality of channels of optical signals; a photonic integrated circuit mounted on the first circuit board and configured to generate a plurality of first serial electrical signals based on the received optical signals; and an array of first electrical terminals arranged on the first surface of the first circuit board, in which the array of first electrical terminals comprises at least two electrical terminals distributed along the length direction and at least two electrical terminals distributed along the width direction, the first electrical terminals are configured to output the first serial electrical signals.

[0011] In another general aspect, a system includes: a housing comprising a bottom surface; a first circuit board comprising a first surface at an angle relative to the bottom surface of the housing, in which the angle is in a range from 30° to 150°; at least one data processor mounted on the first circuit board; and at least one optical interconnect module mounted on the first surface of the first circuit board, in which each optical interconnect module comprises a first optical connector configured to connect to an external optical link, each optical interconnect module comprises a photonic integrated circuit configured to generate a first serial electrical signal based on an optical signal received from the first optical connector; wherein the at least one data processor is configured to process data carried in the first serial electrical signal.

[0012] In another general aspect, a system includes: a housing comprising a front panel, in which the front panel comprises a first circuit board; at least one data processor mounted on the first circuit board; and at least one optical/electrical communication interface mounted on the first circuit board.

[0013] In another general aspect, a system includes: a plurality of rack mount systems, each rack mount system including: a housing comprising a front panel, in which the front panel comprises a first circuit board; at least one data processor mounted on the first circuit board; and at least one optical/electrical communication interface mounted on the first circuit board.

[0014] In another general aspect, a system includes: a housing comprising a front panel; a first circuit board oriented at a first angle relative to the front panel, in which the first angle is in a range from −30° to 30°; at least one data processor mounted on the first circuit board; and at least one optical/electrical communication interface mounted on the first circuit board.

[0015] In another general aspect, a system includes: a plurality of rack mount systems, each rack mount system including: a housing comprising a front panel; a first circuit board oriented at a first angle relative to the front panel, in which the first angle is in a range from −30° to 30°; at least one data processor mounted on the first circuit board; and at least one optical/electrical communication interface mounted on the first circuit board.

[0016] In another general aspect, a system that includes a first optical interconnect module is provided. The first optical interconnect module includes a first optical input/output port configured to at least one of (i) receive a plurality of channels of first optical signals from a first plurality of optical fibers, or (ii) transmit a plurality of channels of second optical signals to the first plurality of optical fibers; a first photonic integrated circuit configured to at least one of (i) generate a plurality of first serial electrical signals based on the first optical signals, or (ii) generate the second optical signals based on a plurality of second serial electrical signals. The first optical interconnect module includes a plurality of first serializer/deserializers configured to at least one of (i) generate a plurality of sets of third parallel electrical signals based on the plurality of first serial electrical signals, and condition the electrical signals, in which each set of third parallel electrical signals is generated based on a corresponding first serial electrical signal, or (ii) generate the plurality of second serial electrical signals based on a plurality of sets of fourth parallel electrical signals, in which each second serial electrical signal is generated based on a corresponding set of fourth parallel electrical signals. The first optical interconnect module includes a plurality of second serializer/deserializers configured to at least one of (i) generate a plurality of fifth serial electrical signals based on the plurality of sets of third parallel electrical signals, in which each fifth serial electrical signal is generated based on a corresponding set of third parallel electrical signals, or (ii) generate the plurality of sets of fourth parallel electrical signals based on a plurality of sixth serial electrical signals, in which each set of fourth parallel electrical signal is generated based on a corresponding sixth serial signal. The system includes a plurality of third serializer/deserializers configured to at least one of (i) generate a plurality of sets of seventh parallel electrical signals based on the plurality of fifth serial electrical signals, and condition the electrical signals, in which each set of seventh parallel electrical signals is generated based on a corresponding fifth serial electrical signal, or (ii) generate the plurality of sixth serial electrical signals based on a plurality of sets of eighth parallel electrical signals, in which each sixth serial electrical signal is generated based on a corresponding set of eighth parallel electrical signals. The system includes a data processor configured to at least one of (i) process the plurality of sets of seventh parallel electrical signals, or (ii) output the plurality of sets of eighth parallel electrical signals.

[0017] In another general aspect, an apparatus includes a substrate, in which the substrate includes: a first main surface and a second main surface; a first array of electrical contacts arranged on the first main surface and having a first minimum spacing between the contacts; a second array of electrical contacts arranged on the second main surface and having a second minimum spacing between the contacts, in which the first minimum spacing is larger than the second minimum spacing; and electrical connections between the first array of electrical contacts and the second array of electrical contacts. The apparatus includes a photonic integrated circuit having a first main surface and a second main surface; a first optical connector part configured to couple light to the first main surface of the photonic integrated circuit; and an electronic integrated circuit having a first main surface that has a first portion and a second portion, in which the first portion of the first main surface is electrically coupled to the second main surface of the photonic integrated circuit, and the second portion of the first main surface is electrically coupled to the second array of electrical contacts arranged on the second main surface of the substrate.

[0018] In another general aspect, an apparatus includes: a printed circuit board having a first main surface and a second main surface; and a substrate. The substrate includes: a first main surface and a second main surface; a first array of electrical contacts arranged on the first main surface and having a first minimum spacing between the contacts; a second array of electrical contacts arranged on the second main surface and having a second minimum spacing between the contacts, in which the first minimum spacing is larger than the second minimum spacing; and electrical connections between the first array of electrical contacts and the second array of electrical contacts; wherein the first main surface of the substrate is configured to be removably connectable to the second main surface of the printed circuit board. The apparatus includes a photonic integrated circuit having a second main surface; a first optical connector part that is optically coupled to the second main surface of the photonic integrated circuit; and an electronic integrated circuit that is electrically coupled to the second main surface of the photonic integrated circuit and the second array of electrical contacts arranged on the second main surface of the substrate.

[0019] In another general aspect, an apparatus includes a printed circuit board having a first main surface and a second main surface; and a substrate. The substrate includes: a first main surface and a second main surface; a first array of electrical contacts arranged on the first main surface and having a first minimum spacing between the contacts; a second array of electrical contacts arranged on the second main surface and having a second minimum spacing between the contacts, in which the first minimum spacing is larger than the second minimum spacing; a third array of electrical contacts arranged on the first main surface; first electrical connections between the first array of electrical contacts and a first subset of the second array of electrical contacts; and second electrical connections between the third array of electrical contacts and a second subset of the second array of electrical contacts; wherein the first main surface of the substrate is configured to be removably connectable to the second main surface of the printed circuit board. The apparatus includes an electronic integrated circuit that is electrically coupled to the second array of electrical contacts arranged on the second main surface of the substrate; a photonic integrated circuit having a second main surface and electrical contacts arranged on the second main surface that are electrically coupled to the third array of electrical contacts arranged on the first main surface of the substrate; and a first optical connector part that is optically coupled to the photonic integrated circuit.

[0020] In another general aspect, a datacenter network switching system that includes any apparatus or system described above.

[0021] In another general aspect, a supercomputer that includes any apparatus or system described above.

[0022] In another general aspect, an autonomous vehicle that includes any apparatus or system described above.

[0023] In another general aspect, a robot that includes any apparatus or system described above.

[0024] In another general aspect, a method includes: receiving a plurality of channels of first optical signals from a plurality of optical fibers; generating a plurality of first serial electrical signals based on the received optical signals, in which each first serial electrical signal is generated based on one of the channels of first optical signals; generating a plurality of sets of first parallel electrical signals based on the plurality of first serial electrical signals, and conditioning the electrical signals, in which each set of first parallel electrical signals is generated based on a corresponding first serial electrical signal; and generating a plurality of second serial electrical signals based on the plurality of sets of first parallel electrical signals, in which each second serial electrical signal is generated based on a corresponding set of first parallel electrical signals.

[0025] In another general aspect, an apparatus includes: a plurality of serializer units; a plurality of deserializer units; and a bus processing unit electrically coupled to the serializer units and deserializer units; wherein the bus processing unit is configured to enable switching of the signals at the serializer units and deserializer units.

[0026] In another general aspect, an apparatus includes: a first array of serializers/deserializers configured to convert one or more first serial signals to one or more sets of parallel signals; a second array of serializers/deserializers configured to convert one or more sets of parallel signals to one or more second serial signals; and a bus processing unit electrically coupled to the first array of serializers/deserializers and the second array of serializers/deserializers, in which the bus processing unit is configured to processing the one or more sets of parallel signals, and send one or more sets of processed parallel signals to the second array of serializers/deserializers.

[0027] In another general aspect, an apparatus includes: a first substrate having a first side and a second side; and a first electronic processor mounted on the first side of the first substrate, in which the first electronic processor is configured to process data; and a first optical interconnect module mounted on the second side of the first substrate. The first optical interconnect module includes: an optical port configured to receive optical signals, and a photonic integrated circuit configured to generate electrical signals based on the received optical signals, and transmit the electrical signals to the first electronic processor.

[0028] Implementations can include one or more of the following features. The first electronic processor can include at least a network switch, a central processor unit, a graphics processor unit, a tensor processing unit, a neural network processor, an artificial intelligence accelerator, a digital signal processor, a microcontroller, an application specific integrated circuit (ASIC), or a data storage device.

[0029] The first optical interconnect module can include: a first serializers/deserializers module including multiple serializer units and deserializer units, and a second serializers/deserializers module including multiple serializer units and deserializer units. The first photonic integrated circuit can be configured to generate first serial electrical signals based on the received optical signals. The first serializers/deserializers module can be configured to generate first parallel electrical signals based on the first serial electrical signals, and condition the electrical signals. The second serializers/deserializers module can be configured to generate second serial electrical signals based on the first parallel electrical signals, and the second serial electrical signals can be transmitted toward the first electronic processor.

[0030] The apparatus can include a third serializers/deserializers module including multiple serializer units and deserializer units. The third serializers/deserializers module can be configured to generate second parallel electrical signals based on the second serial electrical signals, and transmit the second serial electrical signals to the first electronic processor.

[0031] The first substrate can include electrical connectors that extend from the first side of the first substrate to the second side of the first substrate, and the electrical connectors pass through the first substrate from the first side to the second side in a thickness direction. The first optical interconnect module can be electrically coupled to the first electronic processor by the electrical connectors.

[0032] The electrical connectors can include vias of the first substrate.

[0033] The first substrate can include a first printed circuit board.

[0034] The apparatus can include a first structure attached to the second side of the first substrate and configured to enable the first optical interconnect module to be removably coupled to the first structure.

[0035] The first substrate can include a second surface on the second side of the first substrate, and the second surface can include second electrical contacts that are electrically coupled to the first electronic processor. The first optical interconnect module can include electrical contacts that are electrically coupled to the second electrical contacts on the second surface of the first substrate when the first optical interconnect module is coupled to the first structure.

[0036] The first structure can be configured to enable an optical fiber connector to be removably coupled to the first optical interconnect module.

[0037] The apparatus can include: a second substrate having a first side and a second side; a second electronic processor mounted on the first side of the second substrate, in which the second electronic processor can be configured to process data; and a second optical interconnect module mounted on the second side of the second substrate. The second optical interconnect module can include: an optical port configured to receive optical signals, and a photonic integrated circuit configured to generate electrical signals based on the received optical signals, and transmit the electrical signals to the second electronic processor. The apparatus can include an optical power supply including at least one laser that is configured to provide a first light source to the photonic integrated circuit of the first optical interconnect module through a first optical link and to provide a second light source to the photonic integrated circuit of the second optical interconnect module through a second optical link.

[0038] The first substrate and the second substrate can be disposed in a first housing, and the optical power supply can be disposed in a second housing that is external to the first housing.

[0039] The apparatus can include: a second substrate having a first side and a second side; a second electronic processor mounted on the first side of the second substrate, in which the second electronic processor is configured to process data; and a second optical interconnect module mounted on the second side of the second substrate. The second optical interconnect module can include: an optical port configured to receive optical signals, and a photonic integrated circuit configured to generate electrical signals based on the received optical signals, and transmit the electrical signals to the second electronic processor. The apparatus can include a support structure to support the first and second substrates, in which the second substrate is oriented parallel to the first substrate.

[0040] In another general aspect, a system includes: a plurality of data processing modules, in which each data processing module includes a substrate having a first side and a second side, an electronic processor mounted on the first side of the substrate, and an optical interconnect module mounted on the second side of the substrate. The optical interconnect module includes an optical port configured to receive optical signals, and a photonic integrated circuit configured to generate electrical signals based on the received optical signals and transmit the electrical signals to the electronic processor.

[0041] Implementations can include one or more of the following features. The system can include a structure to support the plurality of data processing modules in a way such that the substrates of the data processing modules are oriented parallel to one another.

[0042] The structure can support the data processing modules in a way such that the substrates are oriented vertically to enhance dissipation of heat from at least one of the data processing module or the optical interconnect module of each data processing module.

[0043] The system can include an optical power supply comprising at least one laser that is configured to provide a plurality of light sources to the plurality of data processing modules, in which at least one light source is provided to the photonic integrated circuit of each data processing module through an optical link.

[0044] The electronic processor of each data processing module can include at least a network switch, a central processor unit, a graphics processor unit, a tensor processing unit, a neural network processor, an artificial intelligence accelerator, a digital signal processor, a microcontroller, an application specific integrated circuit (ASIC), or a data storage device.

[0045] The plurality of data processing modules can include a blade pair that comprises a switch blade and a processor blade, the electronic processor of the switch blade comprises a switch, and the electronic processor of the processor blade is configured to process data provided by the switch.

[0046] In another general aspect, a system includes: a plurality of racks of data processing modules, in which multiple racks are stacked vertically, and each rack includes a plurality of data processing modules. Each data processing module includes a substrate having a first side and a second side, an electronic processor mounted on the first side of the substrate, and an optical interconnect module mounted on the second side of the substrate. The optical interconnect module includes an optical port configured to receive optical signals, and a photonic integrated circuit configured to generate electrical signals based on the received optical signals and transmit the electrical signals to the electronic processor.

[0047] Implementations can include one or more of the following features. The system can include a structure to support the plurality of data processing modules in a way such that the substrates of the data processing modules are oriented parallel to one another.

[0048] The structure can support the data processing modules in a way such that the substrates are oriented vertically to enhance dissipation of heat from at least one of the data processing module or the optical interconnect module of each data processing module.

[0049] The system can include an optical power supply including at least one laser that is configured to provide a plurality of light sources to the plurality of data processing modules. At least one light source is provided to the photonic integrated circuit of each data processing module through an optical link.

[0050] The electronic processor of each data processing module can include at least a network switch, a central processor unit, a graphics processor unit, a tensor processing unit, a neural network processor, an artificial intelligence accelerator, a digital signal processor, a microcontroller, an application specific integrated circuit (ASIC), or a data storage device.

[0051] The plurality of data processing modules can include a blade pair that includes a switch blade and a processor blade, the electronic processor of the switch blade includes a switch, and the electronic processor of the processor blade is configured to process data provided by the switch.

[0052] In another general aspect, a method includes: operating a plurality of data processing modules, in which each data processing module includes a substrate having a first side and a second side, an electronic processor mounted on the first side of the substrate, and an optical interconnect module mounted on the second side of the substrate. The optical interconnect module includes an optical port and a photonic integrated circuit. The method includes receiving optical signals at the optical port; using the photonic integrated circuit to generate electrical signals based on the optical signals received at the optical port; and transmitting the electrical signals from the photonic integrated circuit to the electronic processor through electrical connectors that extend from the first side of the substrate to the second side of the substrate.

[0053] In another general aspect, an apparatus includes: a first substrate having a first side and a second side; a first electronic processor mounted on the first side of the first substrate, in which the first electronic processor is configured to process data; and a first optical interconnect module. The first optical interconnect module includes: an optical port configured to receive optical signals from a first optical fiber cable, and a photonic integrated circuit configured to generate electrical signals based on the received optical signals, and transmit the electrical signals to the first electronic processor. At least one of the first optical interconnect module or the first optical fiber cable extends through or partially through an opening in the first substrate to enable at least a portion of the first optical fiber cable to be positioned on or near the second side of the first substrate.

[0054] Implementations can include one or more of the following features. The first optical interconnect module and the first optical fiber cable can define a signal path that extends from the second side of the substrate through the opening to the first electronic processor.

[0055] The first electronic processor can include at least a network switch, a central processor unit, a graphics processor unit, a tensor processing unit, a neural network processor, an artificial intelligence accelerator, a digital signal processor, a microcontroller, an application specific integrated circuit (ASIC), or a data storage device.

[0056] The first optical interconnect module can include: a first serializers/deserializers module including multiple serializer units and deserializer units, and a second serializers/deserializers module including multiple serializer units and deserializer units. The first photonic integrated circuit can be configured to generate first serial electrical signals based on the received optical signals. The first serializers/deserializers module can be configured to generate first parallel electrical signals based on the first serial electrical signals, and condition the electrical signals. The second serializers/deserializers module can be configured to generate second serial electrical signals based on the first parallel electrical signals, and the second serial electrical signals can be transmitted toward the first electronic processor.

[0057] The apparatus can include a third serializers/deserializers module including multiple serializer units and deserializer units. The third serializers/deserializers module can be configured to generate second parallel electrical signals based on the second serial electrical signals, and transmit the second serial electrical signals to the first electronic processor.

[0058] The first substrate can include a first printed circuit board.

[0059] The apparatus can include: a second substrate having a first side and a second side; a second electronic processor mounted on the first side of the second substrate, in which the second electronic processor is configured to process data; and a second optical interconnect module. The second optical interconnect module includes: an optical port configured to receive optical signals from a second optical fiber cable, and a photonic integrated circuit configured to generate electrical signals based on the received optical signals, and transmit the electrical signals to the second electronic processor. At least one of the second optical interconnect module or the second optical fiber cable extends through or partially through an opening in the second substrate to enable at least a portion of the second optical fiber cable to be positioned on or near the second side of the second substrate.

[0060] The apparatus can include an optical power supply including at least one laser. The optical power supply can be configured to provide a first light source to the photonic integrated circuit of the first optical interconnect module through a first optical link and provide a second light source to the photonic integrated circuit of the second optical interconnect module through a second optical link.

[0061] The first substrate and the second substrate can be disposed in a first housing, and the optical power supply can be disposed in a second housing that is external to the first housing.

[0062] The apparatus can include a support structure to support the first and second substrates. The second substrate can be oriented parallel to the first substrate.

[0063] In another general aspect, a system includes: a plurality of data processing modules, in which each data processing module includes a substrate having a first side and a second side, an electronic processor mounted on the first side of the substrate, and an optical interconnect module. The optical interconnect module includes an optical port configured to receive optical signals from an optical fiber cable, and a photonic integrated circuit configured to generate electrical signals based on the received optical signals and transmit the electrical signals to the electronic processor. For each data processing module, at least one of the optical interconnect module or the optical fiber cable extends through or partially through an opening in the substrate to enable at least a portion of the optical fiber cable to be positioned on or near the second side of the substrate.

[0064] Implementations can include one or more of the following features. The system can include a structure to support the plurality of data processing modules in a way such that the substrates of the data processing modules are oriented parallel to one another.

[0065] The structure can support the data processing modules in a way such that the substrates are oriented vertically to enhance dissipation of heat from at least one of the data processing module or the optical interconnect module of each data processing module.

[0066] For each data processing module, the optical interconnect module and the optical fiber cable can define a signal path that extends from the second side of the substrate through the opening to the electronic processor.

[0067] The system can include an optical power supply including at least one laser. The optical power supply can be configured to provide a plurality of light sources to the plurality of data processing modules, and at least one light source is provided to the photonic integrated circuit of each data processing module through an optical link.

[0068] The electronic processor of each data processing module can include at least a network switch, a central processor unit, a graphics processor unit, a tensor processing unit, a neural network processor, an artificial intelligence accelerator, a digital signal processor, a microcontroller, an application specific integrated circuit (ASIC), or a data storage device.

[0069] The plurality of data processing modules can include a blade pair, which can include a switch blade and a processor blade. The electronic processor of the switch blade can include a switch, and the electronic processor of the processor blade can be configured to process data provided by the switch.

[0070] In another general aspect, a system includes: a plurality of racks of data processing modules, in which multiple racks are stacked vertically, and each rack can include a plurality of data processing modules. Each data processing module includes a substrate having a first side and a second side, an electronic processor mounted on the first side of the substrate, and an optical interconnect module. The optical interconnect module includes an optical port configured to receive optical signals from an optical fiber cable, and a photonic integrated circuit configured to generate electrical signals based on the received optical signals and transmit the electrical signals to the electronic processor. For each data processing module, at least one of the optical interconnect module or the optical fiber cable extends through or partially through an opening in the substrate to enable at least a portion of the optical fiber cable to be positioned on or near the second side of the substrate.

[0071] Implementations can include one or more of the following features. The system can include a structure to support the plurality of data processing modules in a way such that the substrates of the data processing modules are oriented parallel to one another.

[0072] The structure can support the data processing modules in a way such that the substrates are oriented vertically to enhance dissipation of heat from at least one of the data processing module or the optical interconnect module of each data processing module.

[0073] The system can include an optical power supply including at least one laser. The optical power supply can be configured to provide a plurality of light sources to the plurality of data processing modules, and at least one light source is provided to the photonic integrated circuit of each data processing module through an optical link.

[0074] The electronic processor of each data processing module can include at least a network switch, a central processor unit, a graphics processor unit, a tensor processing unit, a neural network processor, an artificial intelligence accelerator, a digital signal processor, a microcontroller, an application specific integrated circuit (ASIC), or a data storage device.

[0075] The plurality of data processing modules can include a blade pair, which can include a switch blade and a processor blade. The electronic processor of the switch blade can include a switch, and the electronic processor of the processor blade can be configured to process data provided by the switch.

[0076] In another general aspect, a method includes: operating a plurality of data processing modules, in which each data processing module can include a substrate having a first side and a second side, an electronic processor mounted on the first side of the substrate, and an optical interconnect module including an optical port and a photonic integrated circuit, the optical port is optically coupled to an optical fiber cable. The method includes, for each data processing module, defining a signal path using the optical fiber cable and the optical interconnect module, in which the signal path extends from the second side of the substrate through an opening in the substrate to the electronic processor; using the photonic integrated circuit to generate electrical signals based on the optical signals received at the optical port; and transmitting the electrical signals from the photonic integrated circuit to the electronic processor.

[0077] In another general aspect, a system includes: a housing that includes a bottom panel and a front panel, wherein the front panel is at an angle relative to the bottom panel in which the angle is in a range from 30 to 150°. The system includes a first circuit board positioned inside the housing, in which the first circuit board has a length, a width, and a thickness, wherein the length is at least twice the thickness, the width is at least twice the thickness, and the first circuit board has a first surface defined by the length and the width. The first surface of the first circuit board is at a first angle relative to the bottom panel in which the first angle is in a range from 30° to 150°. The first surface of the first circuit board is substantially parallel to the front panel or at a second angle relative to the front panel when the front panel is closed in which the second angle is less than 60°. The system includes a first data processing module electrically coupled to the first circuit board; and a first optical interconnect module electrically coupled to the first circuit board. The optical interconnect module is configured to receive first optical signals from a first optical link, convert the first optical signals to first electrical signals, and transmit the first electrical signals to the first data processing module.

[0078] Implementations can include one or more of the following features. The system can include a second circuit board that has a length, a width, and a thickness, in which the length is at least twice the thickness, the width is at least twice the thickness, and the second circuit board has a first surface defined by the length and the width. The first surface of the second circuit board can be substantially parallel to the bottom panel or at an angle relative to the bottom panel in which the angle is less than 20°, and the second circuit board is electrically coupled to the first circuit board.

[0079] The second circuit board can include a motherboard, the first circuit board can include a daughter card, and the motherboard can be configured to provide electrical power to the daughter card.

[0080] The front panel can be spaced apart from the rear panel at a mean distance of at least 12 inches, and the first circuit board can be spaced apart from the front panel at a mean distance of less than 4 inches.

[0081] The first data processing module can include at least a network switch, a central processor unit, a graphics processor unit, a tensor processing unit, a neural network processor, an artificial intelligence accelerator, a digital signal processor, a microcontroller, an application specific integrated circuit (ASIC), or a data storage device.

[0082] In some examples, the first data processing module is capable of processing data from the first optical interconnect module at a rate of at least 25 gigabits per second.

[0083] In some examples, the first data processing module is capable of processing data from one or more optical interconnect modules at a rate of at least 1 gigabits per second.

[0084] In some examples, the first data processing module is capable of processing data from one or more optical interconnect modules at a rate of at least 10 gigabits per second.

[0085] In some examples, the first data processing module is capable of processing data from one or more optical interconnect modules at a rate of at least 100 gigabits per second.

[0086] In some examples, the first data processing module is capable of processing data from one or more optical interconnect modules at a rate of at least 1 terabits per second.

[0087] In some examples, the first data processing module is capable of processing data from one or more optical interconnect modules at a rate of at least 10 terabits per second.

[0088] In some examples, the first data processing module can include an integrated circuit or a system on a chip (SoC) that includes at least one thousand transistors.

[0089] In some examples, the first data processing module can include an integrated circuit or a system on a chip (SoC) that includes at least ten thousand transistors.

[0090] In some examples, the first data processing module can include an integrated circuit or a system on a chip (SoC) that includes at least one hundred thousand transistors.

[0091] In some examples, the first data processing module can include an integrated circuit or a system on a chip (SoC) that includes at least one million transistors.

[0092] In some examples, the first data processing module can include an integrated circuit or a system on a chip (SoC) that includes at least ten million transistors.

[0093] In some examples, the first data processing module can include an integrated circuit or a system on a chip (SoC) that includes at least one hundred million transistors.

[0094] In some examples, the first data processing module can include an integrated circuit or a system on a chip (SoC) that includes at least one billion transistors.

[0095] In some examples, the first data processing module can include an integrated circuit or a system on a chip (SoC) that includes at least ten billion transistors.

[0096] In some examples, the first data processing module includes circuitry that is capable of operating at a frequency of 1 MHz or more.

[0097] In some examples, the first data processing module includes circuitry that is capable of operating at a frequency of 10 MHz or more.

[0098] In some examples, the first data processing module includes circuitry that is capable of operating at a frequency of 100 MHz or more.

[0099] In some examples, the first data processing module includes circuitry that is capable of operating at a frequency of 1 GHz or more.

[0100] In some examples, the first data processing module includes circuitry that is capable of operating at a frequency of 3 GHz or more.

[0101] The system can include a rackmount server, the housing includes an enclosure for the rackmount server, and the rackmount server has an n rack unit form factor, and n is an integer in a range from 1 to 8.

[0102] The first data processing module can be mounted on a substrate, and the substrate can be electrically coupled to the first circuit board.

[0103] The first optical interconnect module can be releasably coupled to the first circuit board.

[0104] A socket can be mounted on the first circuit board, and the first optical interconnect module can be releasably coupled to the socket.

[0105] The first optical interconnect module can include a photonic integrated circuit mounted on a substrate, and the substrate can be electrically coupled to the first circuit board.

[0106] The first optical interconnect module can include a connector part that enables one or more optical fibers to be releasably connected to the first optical interconnect module.

[0107] The optical interconnect module can be mounted on the first surface of the first circuit board, and the first surface can face the rear panel and away from the front panel.

[0108] The first circuit board can define a first opening, the front panel can define a second opening, the system can include an optical path that passes through the first and second openings and enables the first optical signals from the first optical link to be transmitted to the first optical interconnect module.

[0109] The first electrical signals can include first serial electrical signals. The system can include: a first serializer/deserializer configured to generate a set of first parallel electrical signals based on the first serial electrical signals, and condition the first parallel electrical signals; and a second serializer/deserializer configured to generate a second serial electrical signal based on the set of first parallel electrical signals. The first data processing module can be configured to process data carried in the second serial electrical signal.

[0110] The system can include a third serializer/deserializer configured to generate a set of second parallel electrical signals based on the second serial electrical signal. The first data processing module can be configured to process data carried by the set of second parallel electrical signals.

[0111] The third serializer/deserializer can be embedded in the first data processing module.

[0112] The first optical interconnect module can include a photonic integrated circuit and a first optical connector optically coupled to the photonic integrated circuit, the first optical connector can be configured to releasably connect with a second optical connector that is coupled to a bundle of at least 100 optical fibers, and the first optical connector can be configured to provide at least 100 optical paths to enable optical signals from the bundle of optical fibers to be coupled to the photonic integrated circuit.

[0113] The first optical interconnect module can include at least one grating coupler, at least one optical waveguide coupled to the grating coupler, and at least one photodetector coupled to the at least one optical waveguide.

[0114] The first optical interconnect module can include an array of grating couplers, a plurality of optical waveguides coupled to the array of grating couplers, and a plurality of photodetectors coupled to the plurality of optical waveguides.

[0115] The first optical interconnect module can include a photonic integrated circuit and an optical fiber connector coupled to the photonic integrated circuit. The photonic integrated circuit can include the array of grating couplers, the plurality of optical waveguides, and the plurality of photodetectors. The optical fiber connector can include an array of lenses configured to focus light to or from the grating couplers.

[0116] In another general aspect, a system includes: a housing includes a front panel, in which the front panel includes a first circuit board; at least one data processing module electrically coupled to the first circuit board; and at least one optical/electrical communication interface electrically coupled to the first circuit board.

[0117] In another general aspect, a system includes: a housing includes a front panel; a first circuit board oriented at a first angle relative to the front panel, in which the first angle is in a range from −60° to 60°; at least one data processor electrically coupled to the first circuit board; and at least one optical/electrical communication interface electrically coupled to the first circuit board.

[0118] In another general aspect, a system includes: a plurality of rack mount systems, each rack mount system includes: a housing includes a front panel, in which the front panel includes a first circuit board; at least one data processor electrically coupled to the first circuit board; and at least one optical/electrical communication interface electrically coupled to the first circuit board.

[0119] In another general aspect, a system includes: a plurality of rack mount systems, each rack mount system includes: a housing includes a front panel; a first circuit board oriented at a first angle relative to the front panel, in which the first angle is in a range from −60° to 60°; at least one data processor electrically coupled to the first circuit board; and at least one optical/electrical communication interface electrically coupled to the first circuit board.

[0120] In another general aspect, an apparatus includes: a first substrate having a first side and a second side; a first electronic processing module mounted on the first side of the first substrate, wherein the first electronic processing module is configured to process data; and a first optical interconnect module mounted on the second side of the first substrate. The first optical interconnect module includes: an optical port configured to receive optical signals, and a photonic integrated circuit configured to generate electrical signals based on the received optical signals, and transmit the electrical signals to the first electronic processor.

[0121] In another general aspect, a system includes: a housing includes a bottom panel and a front panel; and a first circuit board or a first substrate positioned in the housing, in which the first circuit board or the first substrate is oriented at an angle relative to the bottom panel in which the angle is in a range from 30° to 150°. The front panel of the housing is configured to be movable between a closed position and an open position, when the front panel is at the closed position the first circuit board or the first substrate is positioned behind the front panel and substantially parallel to the front panel or at an angle relative to the front panel in which the angle is less than 60°. The system includes a first lattice structure attached to the first circuit board or the first substrate, in which the first lattice structure defines a first plurality of openings. A plurality of sets of electrical contacts are provided on a surface of the first circuit board or the first substrate, and each of the first plurality of openings of the first lattice structure correspond to one of the sets of electrical contacts and enables an optical interconnect module to pass through the opening and electrically couple to the set of electrical contacts.

[0122] In another general aspect, a system includes: a housing includes a bottom panel and a front panel, the front panel includes a plurality of optical connector parts, each optical connector part is configured to be optically coupled to an external optical fiber cable and an internal optical fiber cable; and a first circuit board or a first substrate positioned in the housing, in which the first circuit board or the first substrate is oriented at an angle relative to the bottom panel in which the angle is in a range from 30° to 150°. The first circuit board or the first substrate is substantially parallel to the front panel or at an angle relative to the front panel in which the angle is less than 60°. The system includes a plurality of optical interconnect modules electrically coupled to the first circuit board; and a plurality of internal optical fiber cables, in which each internal optical fiber cable is optically coupled to one of the optical interconnect modules and a corresponding optical connector part on the front panel.

[0123] Implementations can include one or more of the following features. The front panel of the housing can be configured to be movable between a closed position and an open position, when the front panel is at the closed position the first circuit board or the first substrate is positioned behind the front panel and substantially parallel to the front panel or at an angle relative to the front panel in which the angle is less than 60°.

[0124] In another general aspect, a rackmount system is configured to be placed on a rack during operation, the rackmount system includes: a housing that includes a front panel, in which the housing defines a front opening when the front panel is opened; a first circuit board or a first substrate positioned in the housing; and a data processing module electrically coupled to the first circuit board or the first substrate, in which the data processing module has a throughput of at least 100 gigabits per second. The rackmount system includes a plurality of optical interface modules electrically coupled to a first surface of the first circuit board or the first substrate. At least one of the plurality of optical interface modules are configured to receive first optical signals, convert the first optical signals to first electrical signals, and transmit the first electrical signals to the data processing module, and at least one of the plurality of optical interface modules are configured to receive second electrical signals from the data processing module, convert the second electrical signals to second optical signals, and output the second optical signals. The first surface of the first circuit board or the first substrate is oriented to face towards the front opening to allow the optical interface modules to be accessed after the front panel is opened without removing the rackmount system from the rack, in which accessing the optical interface module includes at least one of attaching the optical interface module to the first circuit board or the first substrate, or removing the optical interface module from the first circuit board or the first substrate.

[0125] In another general aspect, a method includes: electrically coupling a first optical interconnect module to a first surface of a first circuit board of a system, in which the first circuit board is oriented substantially parallel to a front panel of a housing of the system or at an angle relative to the front panel when the front panel is closed in which the angle is less than 60°, and the first surface faces the front panel when the front panel is closed; transmitting first optical signals from an optical fiber cable to the first optical interconnect module; converting, using the first optical interconnect module, the first optical signals to first electrical signals; transmitting the first electrical signals to a data processing module electrically coupled to the first circuit board; and processing, using the data processing module, the first electrical signals.

[0126] In another general aspect, a method includes: opening a front panel of a housing of a system to expose a first surface of a first circuit board of the system and a first optical interconnect module that is electrically coupled to the first surface of the first circuit board, in which the first circuit board is oriented substantially parallel to the front panel or at an angle relative to the front panel when the front panel is closed in which the angle is less than 60°, and the first surface faces the front panel when the front panel is closed. The method includes disconnecting the first optical interconnect module from the first surface of the first circuit board; disconnecting the first optical interconnect module from an optical fiber cable that is optically coupled to the first optical interconnect module; optically coupling a second optical interconnect module to the optical fiber cable; electrically coupling the second optical interconnect module to the first surface of the first circuit board; and closing the front panel.

[0127] In another general aspect, an apparatus includes: a co-packaged optical module that includes: a photonic integrated circuit; an optical connector coupled to a first surface of the photonic integrated circuit; and a first set of at least two electrical integrated circuits that are coupled to the first surface of the photonic integrated circuit.

[0128] Implementations can include one or more of the following features. The first set of at least two electrical integrated circuits can include two electrical integrated circuits that are positioned on opposite sides of the optical connector along a plane parallel to the first surface of the photonic integrated circuit.

[0129] The first set of at least one electrical integrated circuit can include four electrical integrated circuits that surround three sides of the optical connector along a plane parallel to the first surface of the photonic integrated circuit.

[0130] The co-packaged optical module can includes: a substrate, in which the photonic integrated circuit is mounted on the substrate; and a second set of at least one electrical integrated circuit mounted on the substrate and electrically coupled to the photonic integrated circuit through one or more signal conductors and/or traces.

[0131] The photonic integrated circuit can include at least one of a photodetector or an optical modulator, and the first set of at least one integrated circuit can include at least one of a transimpedance amplifier configured to amplify a current generated by the photodetector or a driver configured to drive the optical modulator.

[0132] The second set of at least one electrical integrated circuit can include a serializers/deserializers module.

[0133] The photonic integrated circuit can include a silicon substrate and an active layer at a second surface that is opposite to the first surface relative to the photonic integrated circuit. The active layer can include grating couplers, and at least one of photodetectors or optical modulators. The optical connector can be optically coupled to the grating couplers using backside illumination. The first set of at least one electrical integrated circuits can be coupled to the at least one of photodetectors or optical modulators using through silicon vias.

[0134] In another general aspect, an apparatus includes: a co-packaged optical module that includes: a photonic integrated circuit; an optical connector coupled to a first surface of the photonic integrated circuit; and a first set of at least one electrical integrated circuit that is coupled to a second surface of the photonic integrated circuit, in which the second surface is opposite to the first surface relative to the photonic integrated circuit.

[0135] Implementations can include one or more of the following features. The photonic integrated circuit can include an active layer at the first surface, and the active layer can include grating couplers, and at least one of photodetectors or optical modulators. The optical connector can have a footprint that overlaps a footprint of the grating couplers. The at least one of photodetectors or optical modulators are spaced apart from the grating couplers. The first set of at least one electrical integrated circuits can be coupled to the at least one of photodetectors or optical modulators using through silicon vias.

[0136] The photonic integrated circuit can include a silicon substrate and an active layer at the second surface. The active layer can include grating couplers, and at least one of photodetectors or optical modulators. The optical connector can be optically coupled to the grating couplers using backside illumination. The at least one of photodetectors or optical modulators can be spaced apart from the grating couplers, and the first set of at least one electrical integrated circuits can be electrically coupled to the at least one of photodetectors or optical modulators.

[0137] The photonic integrated circuit can include at least one of a photodetector or an optical modulator, and the first set of at least one integrated circuit can include at least one of a transimpedance amplifier configured to amplify a current generated by the photodetector or a driver configured to drive the optical modulator.

[0138] The co-packaged optical module can include: a substrate, in which the photonic integrated circuit is mounted on the substrate; and a second set of at least one electrical integrated circuit mounted on the substrate and electrically coupled to the photonic integrated circuit through one or more signal conductors and/or traces.

[0139] The second set of at least one electrical integrated circuit can include a serializers/deserializers module.

[0140] Other aspects include other combinations of the features recited above and other features, expressed as methods, apparatus, systems, program products, and in other ways.

[0141] Interconnecting electronic chip packages using optical signals can have the advantage that the optical signals can be delivered with a higher input/output capacity per unit area compared to electrical input/outputs.

[0142] Particular embodiments of the subject matter described in this specification can be implemented to realize one or more of the following advantages. The data processing system has a high power efficiency, a low construction cost, a low operation cost, and high flexibility in reconfiguring optical network connections.

[0143] The details of one or more embodiments of the subject matter described in this specification are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages of the invention will become apparent from the description, the drawings, and the claims.

[0144] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict with patent applications or patent application publications incorporated herein by reference, the present specification, including definitions, will control.

[0292] This document describes a novel system for high bandwidth data processing, including novel input/output interface modules for coupling bundles of optical fibers to data processing integrated circuits (e.g., network switches, central processing units, graphics processor units, tensor processing units, digital signal processors, and/or other application specific integrated circuits (ASICs)) that process the data transmitted through the optical fibers. In some implementations, the data processing integrated circuit is mounted on a circuit board positioned near the input/output interface module through a relatively short electrical signal path on the circuit board. The input/output interface module includes a first connector that allows a user to conveniently connect or disconnect the input/output interface module to or from the circuit board. The input/output interface module includes a second connector that allows the user to conveniently connect or disconnect the bundle of optical fibers to or from the input/output interface module. In some implementations, a rack mount system having a front panel is provided in which the circuit board (which supports the input/output interface modules and the data processing integrated circuits) is vertically mounted in an orientation substantially parallel to, and positioned near, the front panel. In some examples, the circuit board functions as the front panel or part of the front panel. The second connectors of the input/output interface modules face the front side of the rack mount system to allow the user to conveniently connect or disconnect bundles of optical fibers to or from the system.

[0293] In some implementations, a feature of the high bandwidth data processing system is that, by vertically mounting the circuit board that supports the input/output interface modules and the data processing integrated circuits to be near the front panel, or configuring the circuit board as the front panel or part of the front panel, the optical signals can be routed from the optical fibers through the input/output interface modules to the data processing integrated circuits through relatively short electrical signal paths. This allows the signals transmitted to the data processing integrated circuits to have a high bit rate (e.g., over 50 Gbps) while maintaining low crosstalk, distortion, and noise, hence reducing power consumption and footprint of the data processing system.

[0294] In some implementations, a feature of the high bandwidth data processing system is that the cost of maintenance and repair can be lower compared to traditional systems. For example, the input/output interface modules and the fiber optic cables are configured to be detachable, a defective input/output interface module can be replaced without taking apart the data processing system and without having to re-route any optical fiber. Another feature of the high bandwidth data processing system is that, because the user can easily connect or disconnect the bundles of the optical fibers to or from the input/output interface modules through the front panel of the rack mount system, the configurations for routing of high bit rate signals through the optical fibers to the various data processing integrated circuits is flexible and can easily be modified. For example, connecting a bundle of hundreds of strands of optical fibers to the optical connector of the rack mount system can be almost as simple as plugging a universal serial bus (USB) cable into a USB port. A further feature of the high bandwidth data processing system is that the input/output interface module can be made using relatively standard, low cost, and energy efficient components so that the initial hardware costs and subsequent operational costs of the input/output interface modules can be relatively low, compared to conventional systems.

[0295] In some implementations, optical interconnects can co-package and/or co-integrate optical transponders with electronic processing chips. It is useful to have transponder solutions that consume relatively low power and that are sufficiently robust against significant temperature variations as may be found within an electronic processing chip package. In some implementations, high speed and/or high bandwidth data processing systems can include massively spatially parallel optical interconnect solutions that multiplex information onto relatively few wavelengths and use a relatively large number of parallel spatial paths for chip-to-chip interconnection. For example, the relatively large number of parallel spatial paths can be arranged in two-dimensional arrays using connector structures such as those disclosed in U.S. patent application Ser. No. 16/816,171, filed on Mar. 11, 2020, and incorporated herein by reference in its entirety.

[0296] FIG. 1 shows a block diagram of a communication system 100 that incorporates one or more novel features described in this document. In some implementations, the system 100 includes nodes 101_1 to 101_6 (collectively referenced as 101), which in some embodiments can each include one or more of: optical communication devices, electronic and/or optical switching devices, electronic and/or optical routing devices, network control devices, traffic control devices, synchronization devices, computing devices, and data storage devices. The nodes 101_1 to 101_6 can be suitably interconnected by optical fiber links 102_1 to 102_12 (collectively referenced as 102) establishing communication paths between the communication devices within the nodes. The optical fiber links 102 can include the fiber-optic cables described in U.S. patent application Ser. No. 16/822,103 filed on Mar. 18, 2020 and incorporated herein by reference in its entirety. The system 100 can also include one or more optical power supply modules 103 producing one or more light outputs, each light output comprising one or more continuous-wave (CW) optical fields and/or one or more trains of optical pulses for use in one or more of the optical communication devices of the nodes 101_1 to 101_6. For illustration purposes, only one such optical power supply module 103 is shown in FIG. 1. A person of ordinary skill in the art will understand that some embodiments can have more than one optical power supply module 103 appropriately distributed over the system 100 and that such multiple power supply modules can be synchronized, e.g., using some of the techniques disclosed in U.S. patent application Ser. No. 16/847,705 filed on Apr. 14, 2020 and incorporated herein by reference in its entirety.

[0297] Some end-to-end communication paths can pass through an optical power supply module 103 (e.g., see the communication path between the nodes 101_2 and 101_6). For example, the communication path between the nodes 101_2 and 101_6 can be jointly established by the optical fiber links 102_7 and 102_8, whereby light from the optical power supply module 103 is multiplexed onto the optical fiber links 102_7 and 102_8.

[0298] Some end-to-end communication paths can pass through one or more optical multiplexing units 104 (e.g., see the communication path between the nodes 101_2 and 101_6). For example, the communication path between the nodes 101_2 and 101_6 can be jointly established by the optical fiber links 102_10 and 102_11. Multiplexing unit 104 is also connected, through the link 102_9, to receive light from the optical power supply module 103 and, as such, can be operated to multiplex said received light onto the optical fiber links 102_10 and 102_11.

[0299] Some end-to-end communication paths can pass through one or more optical switching units 105 (e.g., see the communication path between the nodes 101_1 and 101_4). For example, the communication path between the nodes 101_1 and 101_4 can be jointly established by the optical fiber links 102_3 and 102_12, whereby light from the optical fiber links 102_3 and 102_4 is either statically or dynamically directed to the optical fiber link 102_12.

[0300] As used herein, the term “network element” refers to any element that generates, modulates, processes, or receives light within the system 100 for the purpose of communication. Example network elements include the node 101, the optical power supply module 103, the optical multiplexing unit 104, and the optical switching unit 105.

[0301] Some light distribution paths can pass through one or more network elements. For example, optical power supply module 103 can supply light to the node 101_4 through the optical fiber links 102_7, 102_4, and 102_12, letting the light pass through the network elements 101_2 and 105.

[0302] Various elements of the communication system 100 can benefit from the use of optical interconnects, which can use photonic integrated circuits comprising optoelectronic devices, co-packaged and/or co-integrated with electronic chips comprising integrated circuits.

[0303] As used herein, the term “photonic integrated circuit” (or PIC) should be construed to cover planar lightwave circuits (PLCs), integrated optoelectronic devices, wafer-scale products on substrates, individual photonic chips and dies, and hybrid devices. A substrate can be made of, e.g., one or more ceramic materials, or organic “high density build-up” (HDBU). Example material systems that can be used for manufacturing various photonic integrated circuits can include but are not limited to III-V semiconductor materials, silicon photonics, silica-on-silicon products, silica-glass-based planar lightwave circuits, polymer integration platforms, lithium niobate and derivatives, nonlinear optical materials, etc. Both packaged devices (e.g., wired-up and/or encapsulated chips) and unpackaged devices (e.g., dies) can be referred to as planar lightwave circuits.

[0304] Photonic integrated circuits are used for various applications in telecommunications, instrumentation, and signal-processing fields. In some implementations, a photonic integrated circuit uses optical waveguides to implement and/or interconnect various circuit components, such as for example, optical switches, couplers, routers, splitters, multiplexers/demultiplexers, filters, modulators, phase shifters, lasers, amplifiers, wavelength converters, optical-to-electrical (O/E) and electrical-to-optical (E/O) signal converters, etc. For example, a waveguide in a photonic integrated circuit can be an on-chip solid light conductor that guides light due to an index-of-refraction contrast between the waveguide's core and cladding. A photonic integrated circuit can include a planar substrate onto which optoelectronic devices are grown by an additive manufacturing process and/or into which optoelectronic devices are etched by a subtractive manufacturing processes, e.g., using a multi-step sequence of photolithographic and chemical processing steps.

[0305] In some implementations, an “optoelectronic device” can operate on both light and electrical currents (or voltages) and can include one or more of: (i) an electrically driven light source, such as a laser diode; (ii) an optical amplifier; (iii) an optical-to-electrical converter, such as a photodiode; and (iv) an optoelectronic component that can control the propagation and/or certain properties (e.g., amplitude, phase, polarization) of light, such as an optical modulator or a switch. The corresponding optoelectronic circuit can additionally include one or more optical elements and/or one or more electronic components that enable the use of the circuit's optoelectronic devices in a manner consistent with the circuit's intended function. Some optoelectronic devices can be implemented using one or more photonic integrated circuits.

[0306] As used herein, the term “integrated circuit” (IC) should be construed to encompass both a non-packaged die and a packaged die. In a typical integrated circuit-fabrication process, dies (chips) are produced in relatively large batches using wafers of silicon or other suitable material(s). Electrical and optical circuits can be gradually created on a wafer using a multi-step sequence of photolithographic and chemical processing steps. Each wafer is then cut (“diced”) into many pieces (chips, dies), each containing a respective copy of the circuit that is being fabricated. Each individual die can be appropriately packaged prior to being incorporated into a larger circuit or be left non-packaged.

[0307] The term “hybrid circuit” can refer to a multi-component circuit constructed of multiple monolithic integrated circuits, and possibly some discrete circuit components, all attached to each other to be mountable on and electrically connectable to a common base, carrier, or substrate. A representative hybrid circuit can include (i) one or more packaged or non-packaged dies, with some or all of the dies including optical, optoelectronic, and/or semiconductor devices, and (ii) one or more optional discrete components, such as connectors, resistors, capacitors, and inductors. Electrical connections between the integrated circuits, dies, and discrete components can be formed, e.g., using patterned conducting (such as metal) layers, ball-grid arrays, solder bumps, wire bonds, etc. Electrical connections can also be removable, e.g., by using land-grid arrays and/or compression interposers. The individual integrated circuits can include any combination of one or more respective substrates, one or more redistribution layers (RDLs), one or more interposers, one or more laminate plates, etc.

[0308] In some embodiments, individual chips can be stacked. As used herein, the term “stack” refers to an orderly arrangement of packaged or non-packaged dies in which the main planes of the stacked dies are substantially parallel to each other. A stack can typically be mounted on a carrier in an orientation in which the main planes of the stacked dies are parallel to each other and/or to the main plane of the carrier.

[0309] A “main plane” of an object, such as a die, a photonic integrated circuit, a substrate, or an integrated circuit, is a plane parallel to a substantially planar surface thereof that has the largest sizes, e.g., length and width, among all exterior surfaces of the object. This substantially planar surface can be referred to as a main surface. The exterior surfaces of the object that have one relatively large size, e.g., length, and one relatively small size, e.g., height, are typically referred to as the edges of the object.

[0310] FIG. 2 is a schematic cross-sectional diagram of a data processing system 200 that includes an integrated optical communication device 210 (also referred to as an optical interconnect module), a fiber-optic connector assembly 220, a package substrate 230, and an electronic processor integrated circuit 240. The data processing system 200 can be used to implement, e.g., one or more of devices 101_1 to 101_6 of FIG. 1. FIG. 3 shows an enlarged cross-sectional diagram of the integrated optical communication device 210.

[0311] Referring to FIGS. 2 and 3, the integrated optical communication device 210 includes a substrate 211 having a first main surface 211_1 and a second main surface 211_2. The main surfaces 211_1 and 211_2, respectively, include arrays of electrical contacts 212_1 and 212_2. In some embodiments, the minimum spacing d₁ between any two contacts within the array of contacts 212_1 is larger than the minimum spacing d₂ between any two contacts within the array of contacts 212_2. In some embodiments the minimum spacing between any two contacts within the array of contacts 212_2 is between 40 and 200 micrometers. In some embodiments, the minimum spacing between any two contacts within the array of contacts 212_1 is between 200 micrometers and 1 millimeter. At least some of the contacts 212_1 are electrically connected through the substrate 211 with at least some of the contacts 212_2. In some embodiments, the contacts 212_1 can be permanently attached to a corresponding array of electrical contacts 232_1 on the package substrate 230. In some embodiments, the contacts 212_1 can include mechanisms to allow the device 210 to be removably connected to the package substrate 230, as indicated by a double arrow 233. For example, the system can include mechanical mechanisms (e.g., one or more snap-on or screw-on mechanisms) to hold the various modules in place. In some embodiments, the contacts 212_1, 212_2, and/or 232_1 can include one or more of solder balls, metal pillars, and/or metal pads, etc. In some embodiments, the contacts 212_1, and/or 232_1 can include one or more of spring-loaded elements, compression interposers, and/or land-grid arrays.

[0312] In some embodiments, the integrated optical communication device 210 can be connected to the electronic processor integrated circuit 240 using traces 231 embedded in one or more layers of the package substrate 230. In some embodiments, the processor integrated circuit 240 can include monolithically embedded therein an array of serializers/deserializers (SerDes) 247 electrically coupled to the traces 231. In some embodiments, the processor integrated circuit 240 can include electronic switching circuitry, electronic routing circuitry, network control circuitry, traffic control circuitry, computing circuitry, synchronization circuitry, time stamping circuitry, and data storage circuitry. In some implementations, the processor integrated circuit 240 can be a network switch, a central processing unit, a graphics processor unit, a tensor processing unit, a digital signal processor, or an application specific integrated circuit (ASIC).

[0313] Because the electronic processor integrated circuit 240 and the integrated communication device 210 are both mounted on the package substrate 230, the electrical connectors or traces 231 can be made shorter, as compared to mounting the electronic processor integrated circuit 240 and the integrated communication device 210 on separate circuit boards. Shorter electrical connectors or traces 231 can transmit signals that have a higher data rate with lower noise, lower distortion, and/or lower crosstalk.

[0314] In some implementations, the electrical connectors or traces can be configured as differential pairs of transmission lines, e.g., in a ground-signal-ground-signal-ground configuration. In some examples, the speed of such signal links can be 10 Gbps or more; 56 Gbps or more; 112 Gbps or more; or 224 Gbps or more.

[0315] In some implementations, the integrated optical communication device 210 further includes a first optical connector part 213 having a first surface 213_1 and a second surface 213_2. The connector part 213 is configured to receive a second optical connector part 223 of the fiber-optic connector assembly 220, optically coupled to the connector part 213 through the surfaces 213_1 and 223_2. In some embodiments the connector part 213 can be removably attached to the connector part 223, as indicated by a double-arrow 234, e.g., through a hole 235 in the package substrate 230. In some embodiments the connector part 213 can be permanently attached to the connector part 223. In some embodiments, the connector parts 213 and 223 can be implemented as a single connector element combining the functions of both the connector parts 213 and 223.

[0316] In some implementations, the optical connector part 223 is attached to an array of optical fibers 226. In some embodiments, the array of optical fibers 226 can include one or more of: single-mode optical fiber, multi-mode optical fiber, multi-core optical fiber, polarization-maintaining optical fiber, dispersion-compensating optical fiber, hollow-core optical fiber, or photonic crystal fiber. In some embodiments, the array of optical fibers 226 can be a linear (1D) array. In some other embodiments, the array of optical fibers 226 can be a two-dimensional (2D) array. For example, the array of optical fibers 226 can include 2 or more optical fibers, 4 or more optical fibers, 10 or more optical fibers, 100 or more optical fibers, 500 or more optical fibers, or 1000 or more optical fibers. Each optical fiber can include, e.g., 2 or more cores, or 10 or more cores, in which each core provides a distinct light path. Each light path can include a multiplex of, e.g., 2 or more, 4 or more, 8 or more, or 16 or more serial optical signals, e.g., by use of wavelength division multiplexing channels, polarization-multiplexed channels, coherent quadrature-multiplexed channels. The connector parts 213 and 223 are configured to establish light paths through the first main surface 211_1 of the substrate 211. For example, the array of optical fibers 226 can includes n1 optical fibers, each optical fiber can include n2 cores, and the connector parts 213 and 223 can establish n1×n2 light paths through the first main surface 211_1 of the substrate 211. Each light path can include a multiplex of n3 serial optical signals, resulting in a total of n1×n2×n3 serial optical signals passing through the connector parts 213 and 223. In some embodiments, the connector parts 213 and 223 can be implemented, e.g., as disclosed in U.S. patent application Ser. No. 16/816,171.

[0317] In some implementations, the integrated optical communication device 210 further includes a photonic integrated circuit 214 having a first main surface 214_1 and a second main surface 214_2. The photonic integrated circuit 214 is optically coupled to the connector part 213 through its first main surface 214_1, e.g., as disclosed in in U.S. patent application Ser. No. 16/816,171. For example, the connector part 213 can be configured to optically couple light to the photonic integrated circuit 214 using optical coupling interfaces, e.g., vertical grating couplers or turning mirrors. In the example above, a total of n1×n2x n3 serial optical signals can be coupled through the connector parts 213 and 223 to the photonic integrated circuit 214. Each serial optical signal is converted to a serial electrical signal by the photonic integrated circuit 214, and each serial electrical signal is transmitted from the photonic integrated circuit 214 to a deserializer unit, or a serializer/deserializer unit, described below.

[0318] In some embodiments, the connector part 213 can be mechanically connected (e.g., glued) to the photonic integrated circuit 214. The photonic integrated circuit 214 can contain active and/or passive optical and/or opto-electronic components including optical modulators, optical detectors, optical phase shifters, optical power splitters, optical wavelength splitters, optical polarization splitters, optical filters, optical waveguides, or lasers. In some embodiments, the photonic integrated circuit 214 can further include monolithically integrated active or passive electronic elements such as resistors, capacitors, inductors, heaters, or transistors.

[0319] In some implementations, the integrated optical communication device 210 further includes an electronic communication integrated circuit 215 configured to facilitate communication between the array of optical fibers 226 and the electronic processor integrated circuit 240. A first main surface 215_1 of the electronic communication integrated circuit 215 is electrically coupled to the second main surface 214_2 of the photonic integrated circuit 214, e.g., through solder bumps, copper pillars, etc. The first main surface 215_1 of the electronic communication integrated circuit 215 is further electrically connected to the second main surface 211_2 of the substrate 211 through the array of electrical contacts 212_2. In some embodiments, the electronic communication integrated circuit 215 can include electrical pre-amplifiers and/or electrical driver amplifiers electrically coupled, respectively, to photodetectors and modulators within the photonic integrated circuit 214 (see also FIG. 14). In some embodiments, the electronic communication integrated circuit 215 can include a first array of serializers/deserializers (SerDes) 216 (also referred to as a serializers/deserializers module) whose serial inputs/outputs are electrically connected to the photodetectors and the modulators of the photonic integrated circuit 214 and a second array of serializers/deserializers 217, whose serial inputs/outputs are electrically coupled to the contacts 212_1 through the substrate 211. Parallel inputs of the array of serializers/deserializers 216 can be connected to parallel outputs of the array of serializers/deserializers 217 and vice versa through a bus processing unit 218, which can be, e.g., a parallel bus of electrical lanes, a cross-connect device, or a re-mapping device (gearbox). For example, the bus processing unit 218 can be configured to enable switching of the signals, allowing the routing of signals to be re-mapped. For example, N×50 Gbps electrical lanes can be remapped into N/2×100 Gbps electrical lanes, N being a positive even integer. An example of a bus processing unit 218 is shown in FIG. 40A.

[0320] For example, the electronic communication integrated circuit 215 includes a first serializers/deserializers module that includes multiple serializer units and multiple deserializer units, and a second serializers/deserializers module that includes multiple serializer units and multiple deserializer units. The first serializers/deserializers module includes the first array of serializers/deserializers 216. The second serializers/deserializers module includes the second array of serializers/deserializers 217.

[0321] In some implementations, the first and second serializers/deserializers modules have hardwired functional units so that which units function as serializers and which units function as deserializers are fixed. In some implementations, the functional units can be configurable. For example, the first serializers/deserializers module is capable of operating as serializer units upon receipt of a first control signal, and operating as deserializer units upon receipt of a second control signal. Likewise, the second serializers/deserializers module is capable of operating as serializer units upon receipt of a first control signal, and operating as deserializer units upon receipt of a second control signal.

[0322] Signals can be transmitted between the optical fibers 226 and the electronic processor integrated circuit 240. For example, signals can be transmitted from the optical fibers 226 to the photonic integrated circuit 214, to the first array of serializers/deserializers 216, to the second array of serializers/deserializers 217, and to the electronic processor integrated circuit 240. Similarly, signals can be transmitted from the electronic processor integrated circuit 240 to the second array of serializers/deserializers 217, to the first array of serializers/deserializers 216, to the photonic integrated circuit 214, and to the optical fibers 226.

[0323] In some implementations, the electronic communication integrated circuit 215 is implemented as a first integrated circuit and a second integrated circuit that are electrically coupled each other. For example, the first integrated circuit includes the array of serializers/deserializers 216, and the second integrated circuit includes the array of serializers/deserializers 217.

[0324] In some implementations, the integrated optical communication device 210 is configured to receive optical signals from the array of optical fibers 226, generate electrical signals based on the optical signals, and transmit the electrical signals to the electronic processor integrated circuit 240 for processing. In some examples, the signals can also flow from the electronic processor integrated circuit 240 to the integrated optical communication device 210. For example, the electronic processor integrated circuit 240 can transmit electronic signals to the integrated optical communication device 210, which generates optical signals based on the received electronic signals, and transmits the optical signals to the array of optical fibers 226.

[0325] In some implementations, the photodetectors of the photonic integrated circuit 214 convert the optical signals transmitted in the optical fibers 226 to electrical signals. In some examples, the photonic integrated circuit 214 can include transimpedance amplifiers for amplifying the currents generated by the photodetectors, and drivers for driving output circuits (e.g., driving optical modulators). In some examples, the transimpedance amplifiers and drivers are integrated with the electronic communication integrated circuit 215. For example, the optical signal in each optical fiber 226 can be converted to one or more serial electrical signals. For example, one optical fiber can carry multiple signals by use of wavelength division multiplexing. The optical signals (and the serial electrical signals) can have a high data rate, such as 50 Gbps, 100 Gbps, or more. The first serializers/deserializers module 216 converts the serial electrical signals to sets of parallel electrical signals. For example, each serial electrical signal can be converted to a set of N parallel electrical signals, in which N can be, e.g., 2, 4, 8, 16, or more. The first serializers/deserializers module 216 conditions the serial electrical signals upon conversion into sets of parallel electrical signals, in which the signal conditioning can include, e.g., one or more of clock and data recovery, and signal equalization. The first serializers/deserializers module 216 sends the sets of parallel electrical signals to the second serializers/deserializers module 217 through the bus processing unit 218. The second serializers/deserializers module 217 converts the sets of parallel electrical signals to high speed serial electrical signals that are output to the electrical contacts 212_2 and 212_1.

[0326] The serializers/deserializers module (e.g., 216, 217) can perform functions such as fixed or adaptive signal pre-distortion on the serialized signal. Also, the parallel-to-serial mapping can use a serialization factor M different from N, e.g., 50 Gbps at the input to the first serializers/deserializers module 216 can become 50×1 Gbps on a parallel bus, and two such parallel buses from two serializers/deserializers modules 216 having a total of 100×1 Gbps can then be mapped to a single 100 Gbps serial signal by the serializers/deserializers module 217. An example of the bus processing unit 218 for performing such mapping is shown in FIG. 40B. Also, the high-speed modulation on the serial side can be different, e.g., the serializers/deserializers module 216 can use 50 Gbps Non-Return-to-Zero (NRZ) modulation whereas the serializers/deserializers module 217 can use 100 Gbps Pulse-Amplitude Modulation 4-Level (PAM4) modulation. In some implementations, coding (line coding or error-correction coding) can be performed at the bus processing unit 218. The first and second serializers/deserializers modules 216 and 217 can be commercially available high quality, low power serializers/deserializers that can be purchased in bulk at a low cost.

[0327] In some implementations, the package substrate 230 can include connectors on the bottom side that connects the package substrate 230 to another circuit board, such as a motherboard. The connection can use, e.g., fixed (e.g., by use of solder connection) or removable (e.g., by use of one or more snap-on or screw-on mechanisms). In some examples, another substrate can be provided between the electronic processor integrated circuit 240 and the package substrate 230.

[0328] Referring to FIG. 4, in some implementations, a data processing system 250 includes an integrated optical communication device 252 (also referred to as an optical interconnect module), a fiber-optic connector assembly 220, a package substrate 230, and an electronic processor integrated circuit 240. The data processing system 250 can be used, e.g., to implement one or more of devices 101_1 to 101_6 of FIG. 1. The integrated optical communication device 252 is configured to receive optical signals, generate electrical signals based on the optical signals, and transmit the electrical signals to the electronic processor integrated circuit 240 for processing. In some examples, the signals can also flow from the electronic processor integrated circuit 240 to the integrated optical communication device 252. For example, the electronic processor integrated circuit 240 can transmit electronic signals to the integrated optical communication device 252, which generates optical signals based on the received electronic signals, and transmits the optical signals to the array of optical fibers 226.

[0329] The system 250 is similar to the data processing system 200 of FIG. 2 except that in the system 250, in the direction of the cross section of the figure, a portion 254 of the top surface of the photonic integrated circuit 214 is not covered by the first serializers/deserializers module 216 and the second serializers/deserializers module 217. For example, the portion 254 can be used to couple to other electronic components, optical components, or electro-optical components, either from the bottom (as shown in FIG. 4) or from the top (as shown in FIG. 6). In some examples, the first serializers/deserializers module 216 can have a high temperature during operation. The portion 254 is not covered by the first serializers/deserializers module 216 and can be less thermally coupled to the first serializers/deserializers module 216. In some examples, the photonic integrated circuit 214 can include modulators that modulate the phases of optical signals by modifying the temperature of waveguides and thereby modifying the refractive indices of the waveguides. In such devices, using the design shown in the example of FIG. 4 can allow the modulators to operate in a more thermally stable environment.

[0330] FIG. 5 shows an enlarged cross-sectional diagram of the integrated optical communication device 252. In some implementations, the substrate 211 includes a first slab 256 and a second slab 258. The first slab 256 provides electrical connectors to fan out the electrical contacts, and the second slab 258 provides a removable connection to the package substrate 230. The first slab 256 includes a first set of contacts arranged on the top surface and a second set of contacts arranged on the bottom surface, in which the first set of contacts has a fine pitch and the second set of contacts has a coarse pitch. The minimum distance between contacts in the second set of contacts is greater than the minimum distance between contacts in the first set of contacts. The second slab 258 can include, e.g., spring-loaded contacts 259.

[0331] Referring to FIG. 6, in some implementations, a data processing system 260 includes an integrated optical communication device 262 (also referred to as an optical interconnect module), a fiber-optic connector assembly 270, a package substrate 230, and an electronic processor integrated circuit 240. The data processing system 260 can be used, e.g., to implement one or more of devices 101_1 to 101_6 of FIG. 1. The integrated optical communication device 262 includes a photonic integrated circuit 264. The photonic integrated circuit 264 can include components that perform functions similar to those of the photonic integrated circuit 214 of FIGS. 2-5. The integrated optical communication device 262 further includes a first optical connector part 266 that is configured to receive a second optical connector part 268 of the fiber-optic connector assembly 270. For example, snap-on or screw-on mechanisms can be used to hold the first and second optical connector parts 266 and 268 together.

[0332] The connector parts 266 and 268 can be similar to the connector parts 213 and 223, respectively, of FIG. 4. In some examples, the optical connector part 268 is attached to an array of optical fibers 272, which can be similar to the fibers 226 of FIG. 4.

[0333] The photonic integrated circuit 264 has a top main surface and bottom main surface. The terms “top” and “bottom” refer to the orientations shown in the figure. It is understood that the devices described in this document can be positioned in any orientation, so for example the “top surface” of a device can be oriented facing downwards or sideways, and the “bottom surface” of the device can be oriented facing upwards or sideways. A difference between the photonic integrated circuit 264 and the photonic integrated circuit 214 (FIG. 4) is that the photonic integrated circuit 264 is optically coupled to the connector part 268 through the top main surface, whereas the photonic integrated circuit 214 is optically coupled to the connector part 213 through the bottom main surface. For example, the connector part 266 can be configured to optically couple light to the photonic integrated circuit 214 using optical coupling interfaces, e.g., vertical grating couplers or turning mirrors, similar to the way that the connector part 213 optically couples light to the photonic integrated circuit 214.

[0334] The integrated optical communication devices 252 (FIG. 4) and 262 (FIG. 6) provide flexibility in the design of the data processing systems, allowing the fiber-optic connector assembly 220 or 270 to be positioned on either side of the package substrate 230.

[0335] Referring to FIG. 7, in some implementations, a data processing system 280 includes an integrated optical communication device 282 (also referred to as an optical interconnect module), a fiber-optic connector assembly 270, a package substrate 230, and an electronic processor integrated circuit 240. The data processing system 280 can be used, e.g., to implement one or more of devices 101_1 to 101_6 of FIG. 1.

[0336] The integrated optical communication device 282 includes a photonic integrated circuit 284, a circuit board 286, a first serializers/deserializers module 216, a second serializers/deserializers module 217, and a control circuit 287. The photonic integrated circuit 284 can include components that perform functions similar to those of the photonic integrated circuit 214 (FIGS. 2-5) and 264 (FIG. 6). The control circuit 287 controls the operation of the photonic integrated circuit 284. For example, the control circuit 287 can control one or more photodetector and/or modulator bias voltages, heater voltages, etc., either statically or adaptively based on one or more sensor voltages that the control circuit 287 can receive from the photonic integrated circuit 284. The integrated optical communication device 282 further includes a first optical connector part 288 that is configured to receive a second optical connector part 268 of the fiber-optic connector assembly 270. The optical connector part 268 is attached to an array of optical fibers 272.

[0337] The circuit board 286 has a top main surface 290 and a bottom main surface 292. The photonic integrated circuit 284 has a top main surface 294 and bottom main surface 296. The first and second serializers/deserializers modules 216, 217 are mounted on the top main surface 290 of the circuit board 286. The top main surface 294 of the photonic integrated circuit 284 has electrical terminals that are electrically coupled to corresponding electrical terminals on the bottom main surface 292 of the circuit board 286. In this example, the photonic integrated circuit 284 is mounted on a side of the circuit board 286 that is opposite to the side of the circuit board 286 on which the first and second serializers/deserializers modules 216, 217 are mounted. The photonic integrated circuit 284 is electrically coupled to the first serializers/deserializers 216 by electrical connectors 300 that pass through the circuit board 286 in the thickness direction. In some embodiments, the electrical connectors 300 can be implemented as vias.

[0338] The connector part 288 has dimensions that are configured such that the fiber-optic connector assembly 270 can be coupled to the connector part 288 without bumping into other components of the integrated optical communication device 282. The connector part 288 can be configured to optically couple light to the photonic integrated circuit 284 using optical coupling interfaces, e.g., vertical grating couplers or turning mirrors, similar to the way that the connector part 213 or 266 optically couples light to the photonic integrated circuit 214 or 264, respectively.

[0339] When the integrated optical communication device 282 is coupled to the package substrate 230, the photonic integrated circuit 284 and the control circuit 287 are positioned between the circuit board 286 and the package substrate 230. The integrated optical communication device 282 includes an array of contacts 298 arranged on the bottom main surface 292 of the circuit board 286. The array of contacts 298 is configured such that after the circuit board 286 is coupled to the package substrate 230, the array of contacts 298 maintains a thickness d3 between the circuit board 286 and the package substrate 230, in which the thickness d3 is slightly larger than the thicknesses of the photonic integrated circuit 284 and the control circuit 287.

[0340] FIG. 8 is an exploded perspective view of the integrated optical communication device 282 of FIG. 7. The photonic integrated circuit 284 includes an array of optical coupling components 310, e.g., vertical grating couplers or turning mirrors, as disclosed in U.S. patent application Ser. No. 16/816,171, that are configured to optically couple light from the optical connector part 288 to the photonic integrated circuit 214. The optical coupling components 310 are densely packed and have a fine pitch so that optical signals from many optical fibers can be coupled to the photonic integrated circuit 284. For example, the minimum distance between adjacent optical coupling components 310 can be as small as, e.g., 5 μm, 10 μm, 50 μm, or 100 μm.

[0341] An array of electrical terminals 312 arranged on the top main surface 294 of the photonic integrated circuit 284 are electrically coupled to an array of electrical terminals 314 arranged on the bottom main surface 292 of the circuit board 286. The array of electrical terminals 312 and the array of electrical terminals 314 have a fine pitch, in which the minimum distance between two adjacent electrical terminals can be as small as, e.g., 10 μm, 40 μm, or 100 μm. An array of electrical terminals 316 arranged on the bottom main surface of the first serializers/deserializers 216 are electrically coupled to an array of electrical terminals 318 arranged on the top main surface 290 of the circuit board 286. An array of electrical terminals 320 arranged on the bottom main surface of the second serializers/deserializers module 217 are electrically coupled an array of electrical terminals 322 arranged on the top main surface 290 of the circuit board 286.

[0342] For example, the arrays of electrical terminals 312, 314, 316, 318, 320, and 322 have a fine pitch (or fine pitches). For simplicity of description, in the example of FIG. 8, for each of the arrays of electrical terminals 312, 314, 316, 318, 320, and 322, the minimum distance between adjacent terminals is d2, which can be in the range of, e.g., 10 μm to 200 μm. In some examples, the minimum distance between adjacent terminals for different arrays of electrical terminals can be different. For example, the minimum distance between adjacent terminals for the arrays of electrical terminals 314 (which are arranged on the bottom surface of the circuit board 286) can be different from the minimum distance between adjacent terminals for the arrays of electrical terminals 318 arranged on the top surface of the circuit board 286. The minimum distance between adjacent terminals for the arrays of electrical terminals 316 of the first serializers/deserializers 216 can be different from the minimum distance between adjacent terminals for the arrays of electrical terminals 320 of the second serializers/deserializers module 217.

[0343] An array of electrical terminals 324 arranged on the bottom main surface of the circuit board 286 are electrically coupled to the array of contacts 298. The array of electrical terminals 324 can have a coarse pitch. For example, the minimum distance between adjacent electrical terminals is d1, which can be in the range of, e.g., 200 μm to 1 mm. The array of contacts 298 can be configured as a module that maintains a distance that is slightly larger than the thicknesses of the photonic integrated circuit 284 and the control circuit 287 (which is not shown in FIG. 8) between the integrated optical communication device 282 and the package substrate 230 after the integrated optical communication device 282 is coupled to the package substrate 230. The array of contacts 298 can include, e.g., a substrate that has embedded spring loaded connectors.

[0344] FIG. 9 is a diagram of an example layout design for optical and electrical terminals of the integrated optical communication device 282 of FIGS. 7 and 8. FIG. 9 shows the layout of the optical and electrical terminals when viewed from the top or bottom side of the device 282. In this example, the photonic integrated circuit 284 has a width of about 5 mm and a length of about 2.2 mm to 18 mm. For the example in which the length of the photonic integrated circuit 284 is about 2.2 mm, the optical signals provided to the photonic integrated circuit 284 can have a total bandwidth of about 1.6 Tbps. For the example in which the length of the photonic integrated circuit is about 18 mm, the optical signals provided to the photonic integrated circuit can have a total bandwidth of about 12.8 Tbps. The width of the integrated optical communication device 282 can be about 8 mm.

[0345] An array 330 of optical coupling components 310 is provided to allow optical signals to be provided to the photonic integrated circuit 284 in parallel. The first serializers/deserializers 216 include an array 332 of electrical terminals 316 arranged on the bottom surface of the first serializers/deserializers 216. The second serializers/deserializers module 217 include an array 334 of electrical terminals 320 arranged on the bottom surface of the second serializers/deserializers module 217. The arrays 332 and 334 of electrical terminals 316, 320 have a fine pitch, and the minimum distance between adjacent terminals can be in the range of, e.g., 40 μm to 200 μm. An array 336 of electrical terminals 324 is arranged on the bottom main surface of the circuit board 286. The array 336 of electrical terminals 324 has a coarse pitch, and the minimum distance between adjacent terminals can be in the range of, e.g., 200 μm to 1 mm. For example, the array 336 of electrical terminals 324 can be part of a compression interposer that has a pitch of about 400 μm between terminals.

[0346] FIG. 10 is a diagram of an example layout design for optical and electrical terminals of the integrated optical communication device 210 of FIG. 2. FIG. 10 shows the layout of the optical and electrical terminals when viewed from the top or bottom side of the device 210. In this embodiment, the photonic integrated circuit 214 is implemented as a single chip. In some embodiments, the photonic integrated circuit 214 can be tiled across multiple chips. Likewise, the electronic communication integrated circuit 215 is implemented as a single chip in this embodiment. In some embodiments, the electronic communication integrated circuit 215 can be tiled cross multiple chips. In this embodiment, the electronic communication integrated circuit 215 is implemented using 16 serializers/deserializers blocks 216_1 to 216_16 that are electrically connected to the photonic integrated circuit 214 and 16 serializers/deserializers blocks 217_1 to 217_16, which are electrically connected to an array of contacts 212_1 by electrical connectors that pass through the substrate 211 in the thickness direction. The 16 serializers/deserializers blocks 216_1 to 216_16 are electrically coupled to the 16 serializers/deserializers blocks 217_1 to 217_16 by bus processing units 218_1 to 218_16, respectively. In this embodiment, each serializers/deserializers block (216 or 217) is implemented using 8 serial differential transmitters (TX) and 8 serial differential receivers (RX). In order to transfer the electrical signals from the serializers/deserializers blocks 217 to ASIC 240, a total of 8×16×2=256 electrical differential signal contacts 212_1 in addition to 8×17×2=272 ground (GND) contacts 212_1 can be used. Other contact arrangements that beneficially reduce crosstalk, e.g., placing a ground contact between every pair of TX and RX contacts, can also be used as will be appreciated by a person skilled in the art. The transmitter contacts are collectively referenced as 340, the receiver contacts are collectively referenced as 342, and the ground contacts are collectively referenced as 344.

[0347] The electrical contacts of the serializers/deserializers blocks 216_1 to 216_12 and 217_1 to 217_12 have a fine pitch, and the minimum distance between adjacent terminals can be in the range of, e.g., 40 μm to 200 μm. The electrical contacts 212_1 have a coarse pitch, and the minimum distance between adjacent terminals can be in the range of, e.g., 200 μm to 1 mm.

[0348] FIG. 11 is a schematic side view of an example data processing system 350, which includes an integrated optical communication device 374, a package substrate 230, and a host application specific integrated circuit 240. The integrated optical communication device 374 and the host application specific integrated circuit 240 are mounted on the top side of the package substrate 230. The integrated optical communication device 374 includes a first optical connector 356 that allows optical signals transmitted in optical fibers to be coupled to the integrated optical communication device 374, in which a portion of the optical fibers connected to the first optical connector 356 are positioned at a region facing the bottom side of the package substrate 230.

[0349] The integrated optical communication device 374 includes a photonic integrated circuit 352, a combination of drivers and transimpedance amplifiers (D/T) 354, a first serializers/deserializers module 216, a second serializers/deserializers module 217, the first optical connector 356, a control module 358, and a substrate 360. The host application specific integrated circuit 240 includes an embedded third serializers/deserializers module 247.

[0350] In this example, the photonic integrated circuit 352, the drivers and transimpedance amplifiers 354, the first serializers/deserializers module 216, and the second serializers/deserializers module 217 are mounted on the top side of the substrate 360. In some embodiments, the drivers and transimpedance amplifiers 354, the first serializers/deserializers module 216, and the second serializers/deserializers module 217 can be monolithically integrated into a single electrical chip. The first optical connector 356 is optically coupled to the bottom side of the photonic integrated circuit 352. The control module 358 is electrically coupled to electrical terminals arranged on the bottom side of the substrate 360, whereas the photonic integrated circuit 352 is connected to electrical terminals arranged on the top side of the substrate 360. The control module 358 is electrically coupled to the photonic integrated circuit 352 through electrical connectors 362 that pass through the substrate 360 in the thickness direction. In some embodiments, the substrate 360 can be removably connected to the package substrate 230, e.g., using a compression interposer or a land grid array.

[0351] The photonic integrated circuit 352 is electrically coupled to the drivers and transimpedance amplifiers 354 through electrical connectors 364 on or in the substrate 360. The drivers and transimpedance amplifiers 354 are electrically coupled to the first serializers/deserializers module 216 by electrical connectors 366 on or in the substrate 360. The second serializers/deserializers module 216 has electrical terminals 370 on the bottom side that are electrically coupled to electrical terminals 366 arranged on the bottom side of the substrate 360 through electrical connectors 368 that pass through the substrate 360 in the thickness direction. The electrical terminals 370 have a fine pitch, whereas the electrical terminals 366 have a coarse pitch. The electrical terminals 366 are electrically coupled to the third serializers/deserializers module 247 through electrical connectors or traces 372 on or in the package substrate 230.

[0352] In some implementations, optical signals are converted by the photonic integrated circuit 352 to electrical signals, which are conditioned by the first serializers/deserializers module 216 (or the second serializers/deserializers module 217), and processed by the host application specific integrated circuit 240. The host application specific integrated circuit 240 generates electrical signals that are converted by the photonic integrated circuit 352 into optical signals.

[0353] FIG. 12 is a schematic side view of an example data processing system 380, which includes an integrated optical communication device 382, a package substrate 230, and a host application specific integrated circuit 240. The integrated optical communication device 382 is similar to the integrated optical communication device 374 (FIG. 11), except that the transimpedance amplifiers and drivers are implemented in a separate chip 384 from the chip housing the serializers/deserializers modules 216 and 217.

[0354] FIG. 13 is a schematic side view of an example data processing system 390 that includes an integrated optical communication device 402, a package substrate 230, and a host application specific integrated circuit (not shown in the figure). The integrated optical communication device 402 includes photonic integrated circuit 392, a first serializers/deserializers module 394, a second serializers/deserializers module 396, a third serializers/deserializers module 398, and a fourth serializers/deserializers module 400 that are mounted on a substrate 410. The photonic integrated circuit 392 can include transimpedance amplifiers and drivers, or such amplifiers and/or drivers can be included in the serializers/deserializers modules 394 and 398. The first serializers/deserializers module 394 and the second serializers/deserializers module 396 are positioned on the right side of the photonic integrated circuit 392. The third serializers/deserializers module 398 and the fourth serializers/deserializers module 400 are positioned on the left side of the photonic integrated circuit 392. Here, the term “left” and “right” refer to the relative positions shown in the figure. It is understood that the system 390 can be positioned in any orientation so that the first serializers/deserializers module 394 and the second serializers/deserializers module 396 are not necessarily at the right side of the photonic integrated circuit 392, and the third serializers/deserializers module 398 and the fourth serializers/deserializers module 400 are not necessarily at the left side of the photonic integrated circuit 392.

[0355] The photonic integrated circuit 392 receives optical signals from a first optical connector 404, generates serial electrical signals based on the optical signals, sends the serial electrical signals to the first and second serializers/deserializers modules 394 and 398. The first and second serializers/deserializers modules 394 and 398 generate parallel electrical signals based on the received serial electrical signals, and send the parallel electrical signals to the third and fourth serializers/deserializers modules 396 and 400, respectively. The third and fourth serializers/deserializers modules 396 and 400 generate serial electrical signals based on the received parallel electrical signals, and send the serial electrical signals to electrical terminals 406 and 408, respectively, arranged on the bottom side of the substrate 410.

[0356] The first optical connector 404 is optically coupled to the bottom side of the photonic integrated circuit 392. In some embodiments, the optical connector 404 can also be placed on the top of the photonic integrated circuit 392 and couple light to the top side of the photonic integrated circuit 392 (not shown in the figure). The first optical connector 404 is optically coupled to a second optical connector, which in turn is optically coupled to a plurality of optical fibers. In the configuration shown in FIG. 13, the first optical connector 404, the second optical connector, and/or the optical fibers pass through an opening 412 in the package substrate 230. The electrical terminals 406 are arranged on the right side of the first optical connector 404, and the electrical terminals 408 are arranged on the left side of the first optical connector 404. The electrical terminals 406 and 408 are configured such that the substrate 410 can be removably coupled to the package substrate 230.

[0357] FIG. 14 is a schematic side view of an example data processing system 420 that includes an integrated optical communication device 428, a package substrate 230, and a host application specific integrated circuit (not shown in the figure). The integrated optical communication device 428 includes a photonic integrated circuit 422 (which does not include a transimpedance amplifier and driver), a first serializers/deserializers module 394, a second serializers/deserializers module 396, a third serializers/deserializers module 398, and a fourth serializers/deserializers module 400 that are mounted on a substrate 410. The integrated optical communication device 428 includes a first set of transimpedance amplifiers and driver circuits 424 positioned at the right of the photonic integrated circuit 422, and a second set of transimpedance amplifiers and driver circuits 426 positioned at the left of the photonic integrated circuit 422. The first set of transimpedance amplifiers and driver circuits 424 is positioned between the photonic integrated circuit 422 and a first serializers/deserializers module 394. The second set of transimpedance amplifiers and driver circuits 424 is positioned between the photonic integrated circuit 422 and a third serializers/deserializers module 398.

[0358] In some implementations, the integrated optical communication device 402 (or 408) can be modified such that the first optical connector 404 couples optical signals to the top side of the photonic integrated circuit 392 (or 422).

[0359] FIG. 32 is a schematic side view of an example data processing system 510 that includes an integrated optical communication device 512, a package substrate 230, and a host application specific integrated circuit (not shown in the figure). The integrated optical communication device 512 includes a substrate 514 that includes a first slab 516 and a second slab 518. The first slab 516 provides electrical connectors to fan out the electrical contacts. The first slab 516 includes a first set of contacts arranged on the top surface and a second set of contacts arranged on the bottom surface, in which the first set of contacts has a fine pitch and the second set of contacts has a coarse pitch. The second slab 518 provides a removable connection to the package substrate 230. A photonic integrated circuit 524 is mounted on the bottom side of the first slab 516. A first optical connector 520 passes through an opening in the substrate 514 and couples optical signals to the top side of the photonic integrated circuit 524.

[0360] A first serializers/deserializers module 394, a second serializers/deserializers module 396, a third serializers/deserializers module 398, and a fourth serializers/deserializers module 400 are mounted on the top side of the first slab 516. The photonic integrated circuit 524 is electrically coupled to the first and third serializers/deserializers modules 394 and 398 by electrical connectors 522 that pass through the substrate 514 in the thickness direction. For example, the electrical connectors 522 can be implemented as vias. In some examples, drivers and transimpedance amplifiers can be integrated in the photonic integrated circuit 524, or integrated in the serializers/deserializers modules 394 and 398. In some examples, the drivers and transimpedance amplifiers can be implemented in a separate chip (not shown in the figure) positioned between the photonic integrated circuit 524 and the serializers/deserializers modules 394 and 398, similar to the example in FIG. 14. A control chip (not shown in the figure) can be provided to control the operation of the photonic integrated circuit 512.

[0361] FIG. 15 is a bottom view of an example of the integrated optical communication device 428 of FIG. 14. The photonic integrated circuit 422 includes modulator and photodetector blocks on both sides of a center line 432 in the longitudinal direction. The photonic integrated circuit 422 includes a fiber coupling region 430 arranged either at the bottom side of the photonic integrated circuit 392 or at the top side of the photonic integrated circuit (see FIG. 32), in which the fiber coupling region 430 includes multiple optical coupling elements 310, e.g., receiver optical coupling elements (RX), transmitter optical coupling elements (TX), and remote optical power supply (e.g., 103 in FIG. 1) optical coupling elements (PS).

[0362] Complementary metal oxide semiconductor (CMOS) transimpedance amplifier and driver blocks 424 are arranged on the right side of the photonic integrated circuit 424, and CMOS transimpedance amplifier and driver blocks 426 are arranged on the left side of the photonic integrated circuit 424. A first serializers/deserializers module 394 and a second serializers/deserializers module 396 are arranged on the right side of the CMOS transimpedance amplifier and driver blocks 424. A third serializers/deserializers module 398 and a fourth serializers/deserializers module 400 are arranged on the left side of the CMOS transimpedance amplifier and driver blocks 426.

[0363] In this example, each of the first, second, third, and fourth serializers/deserializers module 394, 396, 398, 400 includes 8 serial differential transmitter blocks and 8 serial differential receiver blocks. The integrated optical communication device 428 has a width of about 3.5 mm and a length of slightly more than about 3.6 mm.

[0364] FIG. 16 is a bottom view of an example of the integrated optical communication device 428 of FIG. 14, in which the electrical terminals 406 and 408 are also shown. As shown in the figure, the electrical terminals 406 and 408 have a coarse pitch, the minimum distance between terminals in the array of electrical terminals 406 or 408 is much larger than the minimum distance between terminals in the array of electrical terminals of the first, second, third, and fourth serializers/deserializers modules 394, 396, 398, and 400. For example, the array of electrical terminals 406 and 408 can be part of a compression interposer that has a pitch of about 400 μm between terminals.

[0365] In some implementations, the electrical terminals (e.g., 406 and 408) can be arranged in a configuration as shown in FIG. 66. FIG. 66 shows a pad map 1020 that shows the locations of various contact pads as viewed from the bottom of the package. The contact pads occupy an area that is 9.8 mm square, in which 400 μm pitch pads are used.

[0366] The middle rectangle 1022 is a cutout that connects the photonic integrated circuit to the optics that leave from the top of the module. The bigger rectangle 1024 represents the photonic integrated circuit. The two gray rectangles 1026a, 1026b represent circuitry in a serializers/deserializers chip. The serializers/deserializers chip is on positioned the top of the package, and the photonic integrated circuit is positioned on the bottom of the package. The overlap between the photonic integrated circuit and the serializers/deserializers is designed so that vias (not shown in the figure) can directly connect these two integrated circuits through the package.

[0367] In the examples of the data processing systems shown in FIGS. 2-8, 11-14, and 32, the integrated optical communication device (e.g., 210, 252, 262, 282, 374, 382, 402, 428, 512, which includes the photonic integrated circuit and the serializers/deserializers modules) is mounted on the package substrate 230 on the same side (top side in the examples shown in the figures) as the electronic processor integrated circuit (or host application specific integrated circuit) 240. The data processing systems can also be modified such that the integrated optical communication device is mounted on the package substrate 230 on the opposite side as the electronic processor integrated circuit (or host application specific integrated circuit) 240. For example, the electronic processor integrated circuit 240 can be mounted on the top side of the package substrate 230 and one or more integrated optical communication devices of the form disclosed in FIGS. 2-8, 11-14, and 32 can be mounted on the bottom side of the package substrate 230.

[0368] FIG. 17 is a diagram showing four types of integrated optical communication devices that can be used in a data processing system 440. In these examples, the integrated optical communication device does not include serializers/deserializers modules. At least some of the signal conditioning is performed by the serializers/deserializers module(s) in the digital application specific integrated circuit. The integrated optical communication device is mounted on the side of the printed circuit board that is opposite to the side on which the digital application specific integrated circuit is mounted, allowing the connectors to be short.

[0369] In a first example, the data processing system includes a digital application specific integrated circuit 444 mounted on the top side of a substrate 442, and an integrated optical communication device 448 mounted on the bottom side of the first circuit board. In some implementations, the integrated optical communication device 448 includes a photonic integrated circuit 450 and a set of transimpedance amplifiers and drivers 452 that are mounted on the bottom side of a substrate 454 (e.g., a second circuit board). The top side of the photonic integrated circuit 450 is electrically coupled to the bottom side of the substrate 454. A first optical connector part 456 is optically coupled to the bottom side of the photonic integrated circuit 450. The first optical connector part 456 is configured to be optically coupled to a second optical connector part 458 that is optically coupled to a plurality of optical fibers (not shown in the figure). An array of electrical terminals 460 is arranged on the top side of the substrate 454 and configured to enable the integrated optical communication device 448 to be removably coupled to the substrate 442.

[0370] The optical signals from the optical fibers are processed by the photonic integrated circuit 450, which generates serial electrical signals based on the optical signals. The serial electrical signals are amplified by the set of transimpedance amplifiers and drivers 452, which drives the output signals that are transmitted to a serializers/deserializers module 446 embedded in the digital application specific integrated circuit 444.

[0371] In a second example, an integrated optical communication device 462 can be mounted on the bottom side of the substrate 442 to provide an optical/electrical communications interface between the optical fibers and the digital application specific integrated circuit 444. The integrated optical communication device 462 includes a photonic integrated circuit 464 that is mounted on the bottom side of a substrate 454 (e.g., a second circuit board). The top side of the photonic integrated circuit 464 is electrically coupled to the bottom side of the substrate 454. A first optical connector part 456 is optically coupled to the bottom side of the photonic integrated circuit 450. An array of electrical terminals 460 is arranged on the top side of the substrate 454 and configured to enable the integrated optical communication device 462 to be removably coupled to the substrate 442. The integrated optical communication device 462 is similar to the integrated optical communication device 448, except that either the photonic integrated circuit 464 or the serializers/deserializers module 446 includes the set of transimpedance amplifiers and driver circuitry. In some examples, the serializers/deserializers module 446 is configured to directly accept electrical signals emerging from photonic integrated circuit 464, e.g., by having a high enough receiver input impedance that converts the photocurrent generated within the photonic integrated circuit 464 to a voltage swing suitable for further electrical processing. For example, the serializers/deserializers module 446 is configured to have a low transmitter output impedance, and provide an output voltage swing that allows direct driving of optical modulators embedded within the photonic integrated circuit 464.

[0372] In a third example, an integrated optical communication device 466 can be mounted on the bottom side of the substrate 442 to provide an optical/electrical communications interface between the optical fibers and the digital application specific integrated circuit 444. The integrated optical communication device 466 includes a photonic integrated circuit 468 that is mounted on the top side of a substrate 470 (e.g., a second circuit board). The bottom side of the photonic integrated circuit 468 is electrically coupled to the top side of the substrate 470. A first optical connector part 456 is optically coupled to the bottom side of the photonic integrated circuit 468. An array of electrical terminals 460 is arranged on the top side of the substrate 470 and configured to enable the integrated optical communication device 466 to be removably coupled to the substrate 442. In some examples, either the photonic integrated circuit 468 or the serializers/deserializers module 446 includes the set of transimpedance amplifiers and driver circuitry. In some examples, the serializers/deserializers module 446 is configured to directly accept electrical signals emerging from the photonic integrated circuit 464.

[0373] In a fourth example, an integrated optical communication device 472 can be mounted on the bottom side of the substrate 442 to provide an optical/electrical communications interface between the optical fibers and the digital application specific integrated circuit 444. The integrated optical communication device 472 includes a photonic integrated circuit 474 and a set of transimpedance amplifiers and drivers 476 that are mounted on the top side of a substrate 470 (e.g., a second circuit board). The bottom side of the photonic integrated circuit 474 is electrically coupled to the top side of the substrate 470. A first optical connector part 456 is optically coupled to the bottom side of the photonic integrated circuit 468. An array of electrical terminals 460 is arranged on the top side of the substrate 470 and configured to enable the integrated optical communication device 466 to be removably coupled to the substrate 442. The integrated optical communication device 472 is similar to the integrated optical communication device 466, except that neither the photonic integrated circuit 464 nor the serializers/deserializers module 446 include a set of transimpedance amplifiers and driver circuitry, and the set of transimpedance amplifiers and drivers 476 is implemented as a separate integrated circuit.

[0374] FIG. 18 is a diagram of an example octal serializers/deserializers block 480 that includes 8 serial differential transmitters (TX) 482 and 8 serial differential receivers (RX) 484. Each serial differential receiver 484 receives a serial differential signal, generates parallel signals based on the serial differential signal, and provides the parallel signals on the parallel bus 488. Each serial differential transmitter 482 receives parallel signals from the parallel bus 488, generates a serial differential signal based on the parallel signals, and provides the serial differential signal on an output electrical terminal 490. The serializers/deserializers block 480 outputs and/or receives parallel signals through a parallel bus interface 492.

[0375] In the examples described above, such as those shown in FIGS. 2-14, the integrated optical communication device (e.g., 210, 252, 262, 282, 374, 382, 402, 428) includes a first serializers/deserializers module (e.g., 216, 394, 398) and a second serializers/deserializers module (e.g., 217, 396, 400). The first serializers/deserializers module serially interfaces with the photonic integrated circuit, and the second serializers/deserializers module serially interfaces with the electronic processor integrated circuit or host application specific integrated circuit (e.g., 240). In some implementations, the electronic communication integrated circuit 215 includes an array of serializers/deserializers that can be logically partitioned into a first sub-array of serializers/deserializers and a second sub-array of serializers/deserializers. The first sub-array of serializers/deserializers corresponds to the serializers/deserializers module (e.g., 216, 394, 398), and the second sub-array of serializers/deserializers corresponds to the second serializers/deserializers module (e.g., 217, 396, 400).

[0376] FIG. 38 is a diagram of an example octal serializers/deserializers block 480 coupled to a bus processing unit 218. The octal serializers/deserializers block 480 includes 8 serial differential transmitters (TX1 to TX8) 482 and 8 serial differential receivers (RX1 to RX4) 484. In some implementations, the transmitters and receivers are partitioned such that the transmitters TX1, TX2, TX3, TX4 and receivers RX1, RX2, RX3, RX4 form a first serializers/deserializers module 840, and the transmitters TX5, TX6, TX7, TX8 and receivers RX5, RX6, RX7, RX8 form a second serializers/deserializers module 842. Serial electrical signals received at the receivers RX1, RX2, RX3, RX4 are converted to parallel electrical signals and routed by the bus processing unit 218 to the transmitters TX5, TX6, TX7, TX8, which convert the parallel electrical signals to serial electrical signals. For example, the photonic integrated circuit can send serial electrical signals to the receivers RX1, RX2, RX3, RX4, and the transmitters TX5, TX6, TX7, TX8 can transmit serial electrical signals to the electronic processor integrated circuit or host application specific integrated circuit.

[0377] For example, the bus processing unit 218 can re-map the lanes of signals and perform coding on the signals, such that the bit rate and/or modulation format of the serial signals output from the transmitters TX5, TX6, TX7, TX8 can be different from the bit rate and/or modulation format of the serial signals received at the receivers RX1, RX2, RX3, RX4. For example, 4 lanes of T Gbps NRZ serial signals received at the receivers RX1, RX2, RX3, RX4 can be re-encoded and routed to transmitters TX5, TX6 to output 2 lanes of 2×T Gbps PAM4 serial signals.

[0378] Similarly, serial electrical signals received at the receivers RX5, RX6, RX7, RX8 are converted to parallel electrical signals and routed by the bus processing unit 218 to the transmitters TX1, TX2, TX3, TX4, which convert the parallel electrical signals to serial electrical signals. For example, the electronic processor integrated circuit or host application specific integrated circuit can send serial electrical signals to the receivers RX5, RX6, RX7, RX8, and the transmitters TX1, TX2, TX3, TX4 can transmit serial electrical signals to the photonic integrated circuit.

[0379] For example, the bus processing unit 218 can re-map the lanes of signals and perform coding on the signals, such that the bit rate and/or modulation format of the serial signals output from the transmitters TX1, TX2, TX3, TX4 can be different from the bit rate and/or modulation format of the serial signals received at the receivers RX5, RX6, RX7, RX8. For example, 2 lanes of 2×T Gbps PAM4 serial signals received at receivers RX5, RX6 can be re-encoded and routed to the transmitters TX5, TX6, TX7, TX8 to output 4 lanes of T Gbps NRZ serial signals.

[0380] FIG. 39 is a diagram of another example octal serializers/deserializers block 480 coupled to a bus processing unit 218, in which the transmitters and receivers are partitioned such that the transmitters TX1, TX2, TX5, TX6 and receivers RX1, RX2, RX5, RX6 form a first serializers/deserializers module 850, and the transmitters TX3, TX4, TX7, TX8 and receivers RX3, RX4, RX7, RX8 form a second serializers/deserializers module 852. Serial electrical signals received at the receivers RX1, RX2, RX5, RX6 are converted to parallel electrical signals and routed by the bus processing unit 218 to the transmitters TX3, TX4, TX7, TX8, which convert the parallel electrical signals to serial electrical signals. For example, the photonic integrated circuit can send serial electrical signals to the receivers RX1, RX2, RX5, RX6, and the transmitters TX3, TX4, TX7, TX8 can transmit serial electrical signals to the electronic processor integrated circuit or host application specific integrated circuit.

[0381] Similarly, serial electrical signals received at the receivers RX3, RX4, RX7, RX8 are converted to parallel electrical signals and routed by the bus processing unit 218 to the transmitters TX1, TX2, TX5, TX6, which convert the parallel electrical signals to serial electrical signals. For example, the electronic processor integrated circuit or host application specific integrated circuit can send serial electrical signals to the receivers RX3, RX4, RX7, RX8, and the transmitters TX1, TX2, TX5, TX6 can transmit serial electrical signals to the photonic integrated circuit.

[0382] In some implementations, the bus processing unit 218 can re-map the lanes of signals and perform coding on the signals, such that the bit rate and/or modulation format of the serial signals output from the transmitters TX3, TX4, TX7, TX8 can be different from the bit rate and/or modulation format of the serial signals received at the receivers RX1, RX2, RX5, RX6. Similarly, the bus processing unit 218 can re-map the lanes of signals and perform coding on the signals such that the bit rate and/or modulation format of the serial signals output from the transmitters TX1, TX2, TX5, TX6 can be different from the bit rate and/or modulation format of the serial signals received at the receivers RX4, RX4, RX7, RX8.

[0383] FIGS. 38 and 39 show two examples of how the receivers and transmitters can be partitioned to form the first serializers/deserializers module and the second serializers/deserializers module. The partitioning can be arbitrarily determined based on application, and is not limited to the examples shown in FIGS. 38 and 39. The partitioning can be programmable and dynamically changed by the system.

[0384] FIG. 19 is a diagram of an example electronic communication integrated circuit 480 that includes a first octal serializers/deserializers block 482 electrically coupled to a second octal serializers/deserializers block 484. For example, the electronic communication integrated circuit 480 can be used as the electronic communication integrated circuit 215 of FIGS. 2 and 3. The first octal serializers/deserializers block 482 can be used as the first serializers/deserializers module 216, and the second octal serializers/deserializers block 484 can be used as the second serializers/deserializers module 217. For example, the first octal serializers/deserializers block 482 can receive 8 serial differential signals, e.g., through electrical terminals arranged at the bottom side of the block, and generate 8 sets of parallel signals based on the 8 serial differential signals, in which each set of parallel signals is generated based on the corresponding serial differential signal. The first octal serializers/deserializers block 482 can condition serial electrical signals upon conversion into the 8 sets of parallel signals, such as performing clock and data recovery, and/or signal equalization. The first octal serializers/deserializers block 482 transmits the 8 sets of parallel signals to the second octal serializers/deserializers block 484 through a parallel bus 485 and a parallel bus 486. The second octal serializers/deserializers block 484 can generate 8 serial differential signals based on the 8 sets of parallel signals, in which each serial differential signal is generated based on the corresponding set of parallel signals. The second octal serializers/deserializers block 484 can output the 8 serial differential signals through, e.g., electrical terminals arranged at the bottom side of the block.

[0385] Multiple serializers/deserializers blocks can be electrically coupled to multiple serializers/deserializers blocks through a bus processing unit that can be, e.g., a parallel bus of electrical lanes, a static or a dynamically reconfigurable cross-connect device, or a re-mapping device (gearbox). FIG. 33 is a diagram of an example electronic communication integrated circuit 530 that includes a first octal serializers/deserializers block 532 and a second octal serializers/deserializers block 534 electrically coupled to a third octal serializers/deserializers block 536 through a bus processing unit 538. In this example, the bus processing unit 538 is configured to enable switching of the signals, allowing the routing of signals to be re-mapped, in which 8×50 Gbps serial electrical signals using NRZ modulation that are serially interfaced to the first and second octal serializers/deserializers blocks 532 and 534 are re-routed or combined into 8×100 Gbps serial electrical signals using PAM4 modulation that are serially interfaced to the third octal serializers/deserializers block 536. An example of the bus processing unit 538 is shown in FIG. 41A. In some examples, the bus processing unit 538 enables N lanes of T Gbps serial electrical signals to be remapped into N/M lanes of M×T Gbps serial electrical signals, N and M being positive integers, T being a real value, in which the N serially interfacing electrical signals can be modulated using a first modulation format and the M serially interfacing electrical signals can be modulated using a second modulation format.

[0386] In some other examples, the bus processing unit 538 can allow for redundancy to increase reliability. For example, the first and the second serializers/deserializers blocks 532 and 534 can be jointly configured to serially interface to a total of N lanes of T×N/(N−k) Gbps electrical signals, while the third serializers/deserializers block 536 can be configured to serially interface to N lanes of T Gbps electrical signals. The bus processing unit 538 can then be configured to remap the data from only N−k out of the N lanes serially interfacing to the first and the second serializers/deserializers blocks 532 and 534 (carrying an aggregate bit rate of (N−k)×T×N/(N−k)=T×N) to the third serializers/deserializers block 536. This way, the bus processing unit 538 allows fork out of N serially interfacing electrical links to the first and the second serializers/deserializers blocks 532 and 534 to fail while still maintaining an aggregate of T×N Gbps of data serially interfacing to the third serializers/deserializers block 536. The number k is a positive integer. In some embodiments, k can be approximately 1% of N. In some other embodiments, k can be approximately 10% of N. In some embodiment, the selection of which N−k of the N serially interfacing electrical links to the first and the second serializers/deserializers blocks 532 and 534 to remap to the third serializers/deserializers block 536 using bus processing unit 538 can be dynamically selected, e.g., based on signal integrity and signal performance information extracted from the serially interfacing signals by the serializers/deserializers blocks 532 and 534. An example of the bus processing unit 538 is shown in FIG. 41B, in which N=16, k=2, T=50 Gbps.

[0387] In some examples, using the redundancy technique discussed above, the bus processing unit 538 enables N lanes of T×N/(N−k) Gbps serial electrical signals to be remapped into N/M lanes of M×T Gbps serial electrical signals. The bus processing unit 538 enables k out of N serially interfacing electrical links to fail while still maintaining an aggregate of T×N Gbps of data serially interfacing to the third serializers/deserializers block 536.

[0388] FIG. 20 is a functional block diagram of an example data processing system 200, which can be used to implement, e.g., one or more of devices 101_1 to 101_6 of FIG. 1. Without implied limitation, the data processing system 200 is shown as part of the node 101_1 for illustration purposes. The data processing system 200 can be part of any other network element of the system 100. The data processing system 200 includes an integrated communication device 210, a fiber-optic connector assembly 220, a package substrate 230, and an electronic processor integrated circuit 240.

[0389] The connector assembly 220 includes a connector 223 and a fiber array 226. The connector 223 can include multiple individual fiber-optic connectors 423_i (i ∈ {R1 . . . RM; S1 . . . SK; T1 . . . TN} with K, M, and N being positive integers). In some embodiments, some or all of the individual connectors 423_i can form a single physical entity. In some embodiments some or all of the individual connectors 423_i can be separate physical entities. When operating as part of the network element 101_1 of the system 100, (i) the connectors 423_S1 through 423_SK can be connected to optical power supply 103, e.g., through link 102_6, to receive supply light; (ii) the connectors 423_R1 through 423_RM can be connected to the transmitters of the node 101_2, e.g., through the link 102_1, to receive from the node 101_2 optical communication signals; and (iii) the connectors 423_T1 through 423_TN can be connected to the receivers of the node 101_2, e.g., through the link 102_1, to transmit to the node 101_2 optical communication signals.

[0390] In some implementations, the communication device 210 includes an electronic communication integrated circuit 215, a photonic integrated circuit 214, a connector part 213, and a substrate 211. The connector part 213 can include multiple individual optical connectors 413_i to photonic integrated circuit 214 (i ∈ {R1 . . . RM; S1 . . . SK; T1 . . . TN} with K, M, and N being positive integers). In some embodiments, some or all of the individual connectors 413_i can form a single physical entity. In some embodiments some or all of the individual connectors 413_i can be separate physical entities. The optical connectors 413_i are configured to optically couple light to the photonic integrated circuit 214 using optical coupling interfaces 414, e.g., vertical grating couplers, turning mirrors, etc., as disclosed in U.S. patent application Ser. No. 16/816,171.

[0391] In operation, light entering the photonic integrated circuit 214 from the link 102_6 through coupling interfaces 414_S1 through 414_SK can be split using an optical splitter 415. The optical splitter 415 can be an optical power splitter, an optical polarization splitter, an optical wavelength demultiplexer, or any combination or cascade thereof, e.g., as disclosed in U.S. patent application Ser. No. 16/847,705 and in U.S. patent application Ser. No. 16/888,890, filed on Jun. 1, 2020, which is incorporated herein by reference in its entirety. In some embodiments, one or more splitting functions of the splitter 415 can be integrated into the optical coupling interfaces 414 and/or into optical connectors 413. For example, in some embodiments, a polarization-diversity vertical grating coupler can be configured to simultaneously act as a polarization splitter 415 and as a part of optical coupling interface 414. In some other embodiments, an optical connector that includes a polarization-diversity arrangement can simultaneously act as an optical connector 413 and as a polarization splitter 415.

[0392] In some embodiments, light at one or more outputs of the splitter 415 can be detected using a receiver 416, e.g., to extract synchronization information as disclosed in U.S. patent application Ser. No. 16/847,705. In various embodiments, the receiver 416 can include one or more p-i-n photodiodes, one or more avalanche photodiodes, one or more self-coherent receivers, or one or more analog (heterodyne/homodyne) or digital (intradyne) coherent receivers. In some embodiments, one or more opto-electronic modulators 417 can be used to modulate onto light at one or more outputs of the splitter 415 data for communication to other network elements.

[0393] Modulated light at the output of the modulators 417 can be multiplexed in polarization or wavelength using a multiplexer 418 before leaving the photonic integrated circuit 214 through optical coupling interfaces 414_T1 through 414_TN. In some embodiments, the multiplexer 418 is not provided, i.e., the output of each modulator 417 can be directly coupled to a corresponding optical coupling interface 414.

[0394] On the receiver side, light entering the photonic integrated circuit 214 through a coupling interfaces 414_R1 through 414_RM from, e.g., the link 101_2, can first be demultiplexed in polarization and/or in wavelength using an optical demultiplexer 419. The outputs of the demultiplexer 419 are then individually detected using receivers 421. In some embodiments, the demultiplexer 419 is not provided, i.e., the output of each coupling interface 414_R1 through 414_RM can be directly coupled to a corresponding receiver 421. In various embodiments, the receiver 421 can include one or more p-i-n photodiodes, one or more avalanche photodiodes, one or more self-coherent receivers, or one or more analog (heterodyne/homodyne) or digital (intradyne) coherent receivers.

[0395] The photonic integrated circuit 214 is electrically coupled to the integrated circuit 215. In some implementations, the photonic integrated circuit 214 provides a plurality of serial electrical signals to the first serializers/deserializers module 216, which generates sets of parallel electrical signals based on the serial electrical signals, in which each set of parallel electrical signal is generated based on a corresponding serial electrical signal. The first serializers/deserializers module 216 conditions the serial electrical signals, demultiplexes them into the sets of parallel electrical signals and sends the sets of parallel electrical signals to the second serializers/deserializers module 217 through a bus processing unit 218. In some implementations, the bus processing unit 218 enables switching of signals and performs line coding and/or error-correcting coding functions. An example of the bus processing unit 218 is shown in FIG. 42.

[0396] The second serializers/deserializers module 217 generates a plurality of serial electrical signals based on the sets of parallel electrical signals, in which each serial electrical signal is generated based on a corresponding set of parallel electrical signal. The second serializers/deserializers module 217 sends the serial electrical signals through electrical connectors that pass through the substrate 211 in the thickness direction to an array of electrical terminals 500 that are arranged on the bottom surface of the substrate 211. For example, the array of electrical terminals 500 configured to enable the integrated communication device 210 to be easily coupled to, or removed from, the package substrate 230.

[0397] In some implementations, the electronic processor integrated circuit 240 includes a data processor 502 and an embedded third serializers/deserializers module 504. The third serializers/deserializers module 504 receives the serial electrical signals from the second serializers/deserializers module 217, and generates sets of parallel electrical signals based on the serial electrical signals, in which each set of parallel electrical signal is generated based on a corresponding serial electrical signal. The data processor 502 processes the sets of parallel signals generated by the third serializers/deserializers module 504.

[0398] In some implementations, the data processor 502 generates sets of parallel electrical signals, and the third serializers/deserializers module 504 generates serial electrical signals based on the sets of parallel electrical signals, in which each serial electrical signal is generated based on a corresponding set of parallel electrical signal. The serial electrical signals are sent to the second serializers/deserializers module 217, which generates sets of parallel electrical signals based on the serial electrical signals, in which each set of parallel electrical signal is generated based on a corresponding serial electrical signal. The second serializers/deserializers module 217 sends the sets of parallel electrical signals to the first serializers/deserializers module 216 through the bus processing unit 218. The first serializers/deserializers module 216 generates serial electrical signals based on the sets of parallel electrical signals, in which each serial electrical signal is generated based on a corresponding set of parallel electrical signals. The first serializers/deserializers module 216 sends the serial electrical signals to the photonic integrated circuit 214. The opto-electronic modulators 417 modulate optical signals based on the serial electrical signals, and the modulated optical signals are output from the photonic integrated circuit 214 through optical coupling interfaces 414_T1 through 414_TN.

[0399] In some embodiments, supply light from the optical power supply 103 includes an optical pulse train, and synchronization information extracted by the receiver 416 can be used by the serializers/deserializers module 216 to align the electrical output signals of the serializers/deserializers module 216 with respective copies of the optical pulse trains at the outputs of the splitter 415 at the modulators 417. For example, the optical pulse train can be used as an optical power supply at the optical modulator. In some such implementations, the first serializers/deserializers module 216 can include interpolators or other electrical phase adjustment elements.

[0400] Referring to FIG. 21, in some implementations, a data processing system 540 includes an enclosure or housing 542 that has a front panel 544, a bottom panel 546, side panels 548 and 550, a rear panel 552, and a top panel (not shown in the figure). The system 540 includes a printed circuit board 558 that extends substantially parallel to the bottom panel 546. A data processing chip 554 is mounted on the printed circuit board 558, in which the chip 554 can be, e.g., a network switch, a central processor unit, a graphics processor unit, a tensor processing unit, a neural network processor, an artificial intelligence accelerator, a digital signal processor, a microcontroller, or an application specific integrated circuit (ASIC).

[0401] At the front panel 544 are pluggable input/output interfaces 556 that allow the data processing chip 554 to communicate with other systems and devices. For example, the input/output interfaces 556 can receive optical signals from outside of the system 540 and convert the optical signals to electrical signals for processing by the data processing chip 554. The input/output interfaces 556 can receive electrical signals from the data processing chip 554 and convert the electrical signals to optical signals that are transmitted to other systems or devices. For example, the input/output interfaces 556 can include one or more of small form-factor pluggable (SFP), SFP+, SFP28, QSFP, QSFP28, or QSFP56 transceivers. The electrical signals from the transceiver outputs are routed to the data processing chip 554 through electrical connectors on or in the printed circuit board 558.

[0402] In the examples shown in FIGS. 21 to 29B, 69A, 70, 71A, 72, 72A, 74A, 75A, 75C, 76, 77A, 77B, 78, 96 to 98, 100, 110, 112, 113, 115, 117 to 122, 125A to 127, 129, 136 to 149, 159, and 160, various embodiments can have various form factors, e.g., in some embodiments the top panel and the bottom panel 546 can have the largest area, in other embodiments the side panels 548 and 550 can have the largest area, and in yet other embodiments the front panel 544 and the rear panel 552 can have the largest area. In various embodiments, the printed circuit board 558 can be substantially parallel to the two side panels, e.g., the data processing system 540 as shown in FIG. 21 can stand on one of its side panels during normal operation (such that the side panel 550 is positioned at the bottom, and the bottom panel 546 is positioned at the side). In various embodiments, the data processing system 540 can comprise two or more printed circuit boards some of which can be substantially parallel to the bottom panel and some of which can be substantially parallel to the side panels. For example, in some computer systems for machine learning/artificial intelligence applications have vertical circuit boards that are plugged into the systems. As used herein, the distinction between “front” and “back” is made based on where the majority of input/output interfaces 556 are located, irrespective of what a user may consider the front or back of data processing system 540.

[0403] FIG. 22 is a diagram of a top view of an example data processing system 560 that includes a housing 562 having side panels 564 and 566, and a rear panel 568. The system 560 includes a vertically mounted printed circuit board 570 that can also function as the front panel. The surface of the printed circuit board 570 is substantially perpendicular to the bottom panel of the housing 562. The term “substantially perpendicular” is meant to take into account of manufacturing and assembly tolerances, so that if a first surface is substantially perpendicular to a second surface, the first surface is at an angle in a range from 85° to 95° relative to the second surface. On the printed circuit board 570 are mounted a data processing chip 572 and an integrated communication device 574. In some examples, the data processing chip 572 and the integrated communication device 574 are mounted on a substrate (e.g., a ceramic substrate), and the substrate is attached (e.g., electrically coupled) to the printed circuit board 570. The data processing chip 572 can be, e.g., a network switch, a central processor unit, a graphics processor unit, a tensor processing unit, a neural network processor, an artificial intelligence accelerator, a digital signal processor, a microcontroller, or an application specific integrated circuit (ASIC). A heat sink 576 is provided on the data processing chip 572.

[0404] In some implementations, the integrated communication device 574 includes a photonic integrated circuit 586 and an electronic communication integrated circuit 588 mounted on a substrate 594. The electronic communication integrated circuit 588 includes a first serializers/deserializers module 590 and a second serializers/deserializers module 592. The printed circuit board 570 can be similar to the package substrate 230 (FIGS. 2, 4, 11-14), the data processing chip 572 can be similar to the electronic processor integrated circuit or application specific integrated circuit 240, and the integrated communication device 574 can be similar to the integrated communication device 210, 252, 374, 382, 402, 428. In some embodiments, the integrated communication device 574 is soldered to the printed circuit board 570. In some other embodiments, the integrated communication device 574 is removably connected to the printed circuit board 570, e.g., via a land grid array or a compression interposer. Related holding fixtures including snap-on or screw-on mechanisms are not shown in the figure.

[0405] In some examples, the integrated communication device 574 includes a photonic integrated circuit without serializers/deserializers modules, and drivers/transimpedance amplifiers (TIA) are provided separately. In some examples, the integrated communication device 574 includes a photonic integrated circuit and drivers/transimpedance amplifiers but without serializers/deserializers modules.

[0406] The integrated communication device 574 includes a first optical connector 578 that is configured to receive a second optical connector 580 that is coupled to a bundle of optical fibers 582. The integrated communication device 574 is electrically coupled to the data processing chip 572 through electrical connectors or traces 584 on or in the printed circuit board 570. Because the data processing chip 572 and the integrated communication device 574 are both mounted on the printed circuit board 570, the electrical connectors or traces 584 can be made shorter, compared to the electrical connectors that electrically couple the transceivers 556 to the data processing chip 554 of FIG. 21. Using shorter electrical connectors or traces 584 allows the signals to have a higher data rate with lower noise, lower distortion, and/or lower crosstalk. Mounting the printed circuit board 570 perpendicular to the bottom panel of the housing allows for more easily accessible connections to the integrated communication device 574 that may be removed and re-connected without, e.g., removing the housing from a rack.

[0407] In some examples, the bundle of optical fibers 582 can be firmly attached to the photonic integrated circuit 586 without the use of the first and second optical connectors 578, 580.

[0408] The printed circuit board 570 can be secured to the side panels 564 and 566, and the bottom and top panels of the housing using, e.g., brackets, screws, clips, and/or other types of fastening mechanisms. The surface of the printed circuit board 570 can be oriented perpendicular to bottom panel of the housing, or at an angle (e.g., between −60° to 60°) relative to the vertical direction (the vertical direction being perpendicular to the bottom panel). The printed circuit board 570 can have multiple layers, in which the outermost layer (i.e., the layer facing the user) has an exterior surface that is configured to be aesthetically pleasing.

[0409] The first optical connector 578, the second optical connector 580, and the bundle of optical fibers 582 can be similar to those shown in FIGS. 2, 4, and 11-16. As described above, the bundle of fibers 582 can include 10 or more optical fibers, 100 or more optical fibers, 500 or more optical fibers, or 1000 or more optical fibers. The optical signals provided to the photonic integrated circuit 586 can have a high total bandwidth, e.g., about 1.6 Tbps, or about 12.8 Tbps, or more.

[0410] Although FIG. 22 shows one integrated communication device 574, there can be additional integrated communication devices 574 that are electrically coupled to the data processing chip 572. The data processing system 560 can include a second printed circuit board (not shown in the figure) oriented parallel to the bottom panel of the housing 562. The second printed circuit board can support other optical and/or electronic devices, such as storage devices, memory chips, controllers, power supply modules, fans, and other cooling devices.

[0411] In some examples of the data processing system 540 (FIG. 21), the transceiver 556 can include circuitry (e.g., integrated circuits) that perform some type of processing of the signals and/or the data contained in the signals. The signals output from the transceiver 556 need to be routed to the data processing chip 554 through longer signal paths that place a limit on the data rate. In some data processing systems, the data processing chip 554 outputs processed data that are routed to one of the transceivers and transmitted to another system or device. Again, the signals output from the data processing chip 554 need to be routed to the transceiver 556 through longer signal paths that place a limit on the data rate. By comparison, in the data processing system 560 (FIG. 22), the electrical signals that are transmitted between the integrated communication devices 574 and the data processing chip 572 pass through shorter signal paths and thus support a higher data rate.

[0412] FIG. 23 is a diagram of a top view of an example data processing system 600 that includes a housing 602 having side panels 604 and 606, and a rear panel 608. The system 600 includes a vertically mounted printed circuit board 610 that functions as the front panel. The surface of the printed circuit board 610 is substantially perpendicular to the bottom panel of the housing 602. A data processing chip 572 is mounted on an interior side of the printed circuit board 610, and an integrated communication device 612 is mounted on an exterior side of the printed circuit board 610. In some examples, the data processing chip 572 is mounted on a substrate (e.g., a ceramic substrate), and the substrate is attached to the printed circuit board 610. In some embodiments, the integrated communication device 612 is soldered to the printed circuit board 610. In some other embodiments, the integrated communication device 612 is removably connected to the printed circuit board 610, e.g., via a land grid array or a compression interposer. Related holding fixtures including snap-on or screw-on mechanisms are not shown in the figure. A heat sink 576 is provided on the data processing chip 572.

[0413] In some implementations, the integrated communication device 612 includes a photonic integrated circuit 614 and an electronic communication integrated circuit 588 mounted on a substrate 618. The electronic communication integrated circuit 588 includes a first serializers/deserializers module 590 and a second serializers/deserializers module 592. The integrated communication device 612 includes a first optical connector 578 that is configured to receive a second optical connector 580 that is coupled to a bundle of optical fibers 582. The integrated communication device 612 is electrically coupled to the data processing chip 572 through electrical connectors or traces 616 that pass through the printed circuit board 610 in the thickness direction. Because the data processing chip 572 and the integrated communication device 612 are both mounted on the printed circuit board 610, the electrical connectors or traces 616 can be made shorter, thereby allowing the signals to have a higher data rate with lower noise, lower distortion, and/or lower crosstalk. Mounting the integrated communication device 612 on the outside of the printed circuit board 610 perpendicular to the bottom panel of the housing and accessible from outside the housing allows for more easily accessible connections to the integrated communication device 612 that may be removed and re-connected without, e.g., removing the housing from a rack.

[0414] In some examples, the integrated communication device 612 includes a photonic integrated circuit without serializers/deserializers modules, and drivers and transimpedance amplifiers (TIA) are provided separately. In some examples, the integrated communication device 612 includes a photonic integrated circuit and drivers/transimpedance amplifiers but without serializers/deserializers modules. In some examples, the bundle of optical fibers 582 can be firmly attached to the photonic integrated circuit 614 without the use of the first and second optical connectors 578, 580.

[0415] In some examples, the data processing chip 572 is mounted on the rear side of the substrate, and the integrated communication device 612 are removably attached to the front side of the substrate, in which the substrate provides high speed connections between the data processing chip 572 and the integrated communication device 612. For example, the substrate can be attached to a front side of a printed circuit board, in which the printed circuit board includes an opening that allows the data processing chip 572 to be mounted on the rear side of the substrate. The printed circuit board can provide from a motherboard electrical power to the substrate (and hence to the data processing chip 572 and the integrated communication device 612, and allow the data processing chip 572 and the integrated communication device 612 to connect to the motherboard using low-speed electrical links.

[0416] The printed circuit board 610 can be secured to the side panels 604 and 606, and the bottom and top panels of the housing using, e.g., brackets, screws, clips, and/or other types of fastening mechanisms. The surface of the printed circuit board 610 can be oriented perpendicular to bottom panel of the housing, or at an angle (e.g., between −60° to 60°) relative to the vertical direction (the vertical direction being perpendicular to the bottom panel). The printed circuit board 610 can have multiple layers, in which the portion of the outermost layer (i.e., the layer facing the user) not covered by the integrated communication device 612 has an exterior surface that is configured to be aesthetically pleasing.

[0417] FIGS. 24-27 below illustrate four general designs in which the data processing chips are positioned near the input/output communication interfaces. FIG. 24 is a top view of an example data processing system 630 in which a data processing chip 640 is mounted near an optical/electrical communication interface 644 to enable high bandwidth data paths (e.g., one, ten, or more Gigabits per second per data path) between the data processing chip 640 and the optical/electrical communication interface 644. In this example, the data processing chip 640 and the optical/electrical communication interface 644 are mounted on a circuit board 642 that functions as the front panel of an enclosure 632 of the system 630, thus allowing optical fibers to be easily coupled to the optical/electrical communication interface 644. In some examples, the data processing chip 640 is mounted on a substrate (e.g., a ceramic substrate), and the substrate is attached to the circuit board 642.

[0418] The enclosure 632 has side panels 634 and 636, a rear panel 638, a top panel, and a bottom panel. In some examples, the circuit board 642 is perpendicular to the bottom panel. In some examples, the circuit board 642 is oriented at an angle in a range −60° to 60° relative to a vertical direction of the bottom panel. The side of the circuit board 642 facing the user is configured to be aesthetically pleasing.

[0419] The optical/electrical communication interface 644 is electrically coupled to the data processing chip 640 by electrical connectors or traces 646 on or in the circuit board 642. The circuit board 642 can be a printed circuit board that has one or more layers. The electrical connectors or traces 646 can be signal lines printed on the one or more layers of the printed circuit board 642 and provide high bandwidth data paths (e.g., one or more Gigabits per second per data path) between the data processing chip 640 and the optical/electrical communication interface 644.

[0420] In a first example, the data processing chip 640 receives electrical signals from the optical/electrical communication interface 644 and does not send electrical signals to the optical/electrical communication interface 644. In a second example, the data processing chip 640 receives electrical signals from, and sends electrical signals to, the optical/electrical communication interface 644. In the first example, the optical/electrical communication interface 644 receives optical signals from optical fibers, generates electrical signals based on the optical signals, and sends the electrical signals to the data processing chip 640. In the second example, the optical/electrical communication interface 644 also receives electrical signals from the data processing chip, generates optical signals based on the electrical signals, and sends the optical signals to the optical fibers.

[0421] An optical connector 648 is provided to couple optical signals from the optical fibers to the optical/electrical communication interface 644. In this example, the optical connector 648 passes through an opening in the circuit board 642. In some examples, the optical connector 648 is securely fixed to the optical/electrical communication interface 644. In some examples, the optical connector 648 is configured to be removably coupled to the optical/electrical communication interface 644, e.g., by using a pluggable and releasable mechanism, which can include one or more snap-on or screw-on mechanisms. In some other examples, an array of 10 or more fibers is securely or fixedly attached to the optical connector 648.

[0422] The optical/electrical communication interface 644 can be similar to, e.g., the integrated communication device 210 (FIG. 2), 252 (FIG. 4), 374 (FIG. 11), 382 (FIG. 12), 402 (FIG. 13), and 428 (FIG. 14). In some examples, the optical/electrical communication interface 644 can be similar to the integrated optical communication device 448, 462, 466, 472 (FIG. 17), except that the optical/electrical communication interface 644 is mounted on the same side of the circuit board 642 as the data processing chip 640. The optical connector 648 can be similar to, e.g., the first optical connector part 213 (FIGS. 2, 4), the first optical connector 356 (FIGS. 11, 12), the first optical connector 404 (FIGS. 13, 14), and the first optical connector part 456 (FIG. 17). In some examples, a portion of the optical connector 648 can be part of the optical/electrical communication interface 644. In some examples, the optical connector 648 can also include the second optical connector part 223 (FIGS. 2, 4), 458 (FIG. 17) that is optically coupled to the optical fibers. FIG. 24 shows that the optical connector 648 passes through the circuit board 642. In some examples, the optical connector 648 can be short so that the optical fibers pass through, or partly through, the circuit board 642. In some examples, the optical connector is not attached vertically to a photonic integrated circuit that is part of the optical/electrical communication interface 644 but rather can be attached in-plane to the photonic integrated circuit using, e.g., V-groove fiber attachments, tapered or un-tapered fiber edge coupling, etc., followed by a mechanism to direct the light interfacing to the photonic integrated circuit to a direction that is substantially perpendicular to the photonic integrated circuit, such as one or more substantially 90-degree turning mirrors, one or more substantially 90-degree bent optical fibers, etc. Any such solution is conceptually included in the vertical optical coupling attachment schematically visualized in FIGS. 24-27.

[0423] FIG. 25 is a top view of an example data processing system 650 in which a data processing chip 670 is mounted near an optical/electrical communication interface 652 to enable high bandwidth data paths (e.g., one, ten, or more Gigabits per second per data path) between the data processing chip 670 and the optical/electrical communication interface 652. In this example, the data processing chip 670 and the optical/electrical communication interface 652 are mounted on a circuit board 654 that is positioned near a front panel 656 of an enclosure 658 of the system 630, thus allowing optical fibers to be easily coupled to the optical/electrical communication interface 652. In some examples, the data processing chip 670 is mounted on a substrate (e.g., a ceramic substrate), and the substrate is attached to the circuit board 654.

[0424] The enclosure 658 has side panels 660 and 662, a rear panel 664, a top panel, and a bottom panel. In some examples, the circuit board 654 and the front panel 656 are perpendicular to the bottom panel. In some examples, the circuit board 654 and the front panel 656 are oriented at an angle in a range −60° to 60° relative to a vertical direction of the bottom panel. In some examples, the circuit board 654 is substantially parallel to the front panel 656, e.g., the angle between the surface of the circuit board 654 and the surface of the front panel 656 can be in a range of −5° to 5°. In some examples, the circuit board 654 is at an angle relative to the front panel 656, in which the angle is in a range of −45° to 45°.

[0425] The optical/electrical communication interface 652 is electrically coupled to the data processing chip 670 by electrical connectors or traces 666 on or in the circuit board 654, similar to those of the system 630. The signal path between the data processing chip 670 and the optical/electrical communication interface 652 can be unidirectional or bidirectional, similar to that of the system 630.

[0426] An optical connector 668 is provided to couple optical signals from the optical fibers to the optical/electrical communication interface 652. In this example, the optical connector 668 passes through an opening in the front panel 656 and an opening in the circuit board 654. The optical connector 668 can be securely fixed, or releasably connected, to the optical/electrical communication interface 652, similar to that of the system 630.

[0427] The optical/electrical communication interface 652 can be similar to, e.g., the integrated communication device 210 (FIG. 2), 252 (FIG. 4), 374 (FIG. 11), 382 (FIG. 12), 402 (FIG. 13), and 428 (FIG. 14). In some examples, the optical/electrical communication interface 652 can be similar to the integrated optical communication device 448, 462, 466, 472 (FIG. 17), except that the optical/electrical communication interface 652 is mounted on the same side of the circuit board 654 as the data processing chip 640. The optical connector 668 can be similar to, e.g., the first optical connector part 213 (FIGS. 2, 4), the first optical connector 356 (FIGS. 11, 12), the first optical connector 404 (FIGS. 13, 14), and the first optical connector part 456 (FIG. 17). In some examples, the optical connector is not attached vertically to a photonic integrated circuit that is part of the optical/electrical communication interface 652 but rather can be attached in-plane to the photonic integrated circuit using, e.g., V-groove fiber attachments, tapered or un-tapered fiber edge coupling, etc., followed by a mechanism to direct the light interfacing to the photonic integrated circuit to a direction that is substantially perpendicular to the photonic integrated circuit, such as one or more substantially 90-degree turning mirrors, one or more substantially 90-degree bent optical fibers, etc. In some examples, a portion of the optical connector 668 can be part of the optical/electrical communication interface 652. In some examples, the optical connector 668 can also include the second optical connector part 223 (FIGS. 2, 4), 458 (FIG. 17) that is optically coupled to the optical fibers. FIG. 25 shows that the optical connector 668 passes through the front panel 656 and the circuit board 654. In some examples, the optical connector 668 can be short so that the optical fibers pass through, or partly through, the front panel 656. The optical fibers can also pass through, or partly through, the circuit board 654.

[0428] In the examples of FIGS. 24 and 25, only one optical/electrical communication interface (544, 652) is shown in the figures. It is understood that the systems 630, 650 can include multiple optical/electrical communication interfaces that are mounted on the same circuit board as the data processing chip to enable high bandwidth data paths (e.g., one, ten, or more Gigabits per second per data path) between the data processing chip and each of the optical/electrical communication interfaces.

[0429] FIG. 26A is a top view of an example data processing system 680 in which a data processing chip 681 is mounted near optical/electrical communication interfaces 682a, 682b, 682c (collectively referenced as 682) to enable high bandwidth data paths (e.g., one, ten, or more Gigabits per second per data path) between the data processing chip 681 and each of the optical/electrical communication interfaces 682. The data processing chip 681 is mounted on a first side of a circuit board 683 that functions as a front panel of an enclosure 684 of the system 680. In some examples, the data processing chip 681 is mounted on a substrate (e.g., a ceramic substrate), and the substrate is attached to the circuit board 683. The optical/electrical communication interfaces 682 are mounted on a second side of the circuit board 683, in which the second side faces the exterior of the enclosure 684. In this example, the optical/electrical communication interfaces 682 are mounted on an exterior side of the enclosure 684, allowing optical fibers to be easily coupled to the optical/electrical communication interfaces 682.

[0430] The enclosure 684 has side panels 685 and 686, a rear panel 687, a top panel, and a bottom panel. In some examples, the circuit board 683 is perpendicular to the bottom panel. In some examples, the circuit board 683 is oriented at an angle in a range −60° to 60° (or −30° to 30°, or −10° to 10°, or −1° to 1°) relative to a vertical direction of the bottom panel.

[0431] Each of the optical/electrical communication interfaces 682 is electrically coupled to the data processing chip 681 by electrical connectors or traces 688 that pass through the circuit board 683 in the thickness direction. For example, the electrical connectors or traces 688 can be configured as vias of the circuit board 683. The signal paths between the data processing chip 681 and each of the optical/electrical communication interfaces 682 can be unidirectional or bidirectional, similar to those of the systems 630 and 650.

[0432] For example, the system 680 can be configured such that signals are transmitted unidirectionally between the data processing chip 681 and one of the optical/electrical communication interfaces 682, and bidirectionally between the data processing chip 681 and another one of the optical/electrical communication interfaces 682. For example, the system 680 can be configured such that signals are transmitted unidirectionally from the optical/electrical communication interface 682a to the data processing chip 681, and unidirectionally from the data processing chip to the optical/electrical communication interface 682b and/or optical/electrical communication interface 682c.

[0433] Optical connectors 689a, 689b, 689c (collectively referenced as 689) are provided to couple optical signals from the optical fibers to the optical/electrical communication interfaces 682a, 682b, 682c, respectively. The optical connectors 689 can be securely fixed, or releasably connected, to the optical/electrical communication interfaces 682, similar to those of the systems 630 and 650.

[0434] The optical/electrical communication interface 682 can be similar to, e.g., the integrated communication device 210 (FIG. 2), 252 (FIG. 4), 374 (FIG. 11), 382 (FIG. 12), 402 (FIG. 13), 428 (FIG. 14), and 512 (FIG. 32), except that the optical/electrical communication interface 682 is mounted on the side of the circuit board 683 opposite to the side of the data processing chip 681. In some examples, the optical/electrical communication interface 682 can be similar to the integrated optical communication device 448, 462, 466, 472 (FIG. 17). The optical connector 689 can be similar to, e.g., the first optical connector part 213 (FIGS. 2, 4), the first optical connector 356 (FIGS. 11, 12), the first optical connector 404 (FIGS. 13, 14), the first optical connector part 456 (FIG. 17), and the first optical connector part 520 (FIG. 32). In some examples, the optical connector is not attached vertically to a photonic integrated circuit that is part of the optical/electrical communication interface 682 but rather can be attached in-plane to the photonic integrated circuit using, e.g., V-groove fiber attachments, tapered or un-tapered fiber edge coupling, etc., followed by a mechanism to direct the light interfacing to the photonic integrated circuit to a direction that is substantially perpendicular to the photonic integrated circuit, such as one or more substantially 90-degree turning mirrors, one or more substantially 90-degree bent optical fibers, etc. In some examples, a portion of the optical connector 689 can be part of the optical/electrical communication interface 682. In some examples, the optical connector 689 can also include the second optical connector part 223 (FIGS. 2, 4), 458 (FIG. 17) that is optically coupled to the optical fibers.

[0435] In some examples, the optical/electrical communication interfaces 682 are securely fixed (e.g., by soldering) to the circuit board 683. In some examples, the optical/electrical communication interfaces 682 are removably connected to the circuit board 683, e.g., by use of mechanical mechanisms such as one or more snap-on or screw-on mechanisms. An advantage of the system 680 is that in case of a malfunction at one of the optical/electrical communication interfaces 682, the faulty optical/electrical communication interface 682 can be replaced without opening the enclosure 684.

[0436] FIG. 26B is a top view of an example data processing system 690b in which a data processing chip 691b is mounted near optical/electrical communication interfaces 692a, 692b, 692c (collectively referenced as 692) to enable high bandwidth data paths (e.g., one, ten, or more Gigabits per second per data path) between the data processing chip 691b and each of the optical/electrical communication interfaces 692. The data processing chip 691 is mounted on a first side of a circuit board 693b that functions as a front panel of an enclosure 694b of the system 690b. In this example, the optical/electrical communication interface 692a is mounted on the first side of the circuit board 693b and the optical/electrical communication interfaces 692b and 692c are mounted on a second side of the circuit board 693b, in which the second side faces the exterior of the enclosure 694b. In this example, the optical/electrical communication interfaces 692b and 692c are mounted on an exterior side of the enclosure 694b, allowing connection to optical fiber from the front of the enclosure 694b while the optical/electrical communication interface 692a is located internal to the enclosure 694b, for example, to allow connection to optical fiber at the rear of the enclosure 694b. In some examples, two or more of the optical/electrical communication interfaces 692 can be located internal to the enclosure 694b and connect to optical fibers at the rear of the enclosure 694b.

[0437] The enclosure 694b has side panels 695b and 696b, a rear panel 697b, a top panel, and a bottom panel. In some examples, the circuit board 693b is perpendicular to the bottom panel. In some examples, the circuit board 693b is oriented at an angle in a range −60° to 60° (or −30° to 30°, or −10° to 10°, or −1° to 1°) relative to a vertical direction of the bottom panel.

[0438] Each of the optical/electrical communication interfaces 692 is electrically coupled to the data processing chip 691b by electrical connectors or traces 698b that pass through the circuit board 693b in the thickness direction. For example, the electrical connectors or traces 698b can be configured as vias of the circuit board 693b. In this example, the electrical connectors or traces 698b extend to both sides of the circuit board 693b (e.g., for connecting to optical/electrical communication interfaces 692 located internal to and external of the enclosure 694b). The signal paths between the data processing chip 691b and each of the optical/electrical communication interfaces 692 can be unidirectional or bidirectional, similar to those of the systems 630, 650 and 680.

[0439] For example, the system 690b can be configured such that signals are transmitted unidirectionally between the data processing chip 691b and one of the optical/electrical communication interfaces 692, and bidirectionally between the data processing chip 691b and another one of the optical/electrical communication interfaces 692. For example, the system 690b can be configured such that signals are transmitted unidirectionally from the optical/electrical communication interface 692a to the data processing chip 691b, and unidirectionally from the data processing chip 691b to the optical/electrical communication interface 692b and/or optical/electrical communication interface 692c.

[0440] Optical connectors 699a, 699b, 699c (collectively referenced as 699) are provided to couple optical signals from the optical fibers to the optical/electrical communication interfaces 692a, 692b, 692c, respectively. The optical connectors 699 can be securely fixed, or releasably connected, to the optical/electrical communication interfaces 692, similar to those of the systems 630, 650, and 680. In this example, optical connector 699b and optical connector 699c can connect to optical fibers at the front of the enclosure 694b and the optical connector 699a can connect to optical fibers at the rear of the enclosure 694b. In the illustrated example, the optical connector 699a connects to an optical fiber at the rear of the enclosure 694b by being connected to a fiber 1000b that connects to a rear panel interface 1001b (e.g., a backplane, etc.) that is mounted to the rear panel 697b. In some examples, the optical connectors 699 can be securely or fixedly attached to communication interfaces 692. In some examples, the optical connectors 699 can be securely or fixedly attached to an array of optical fibers.

[0441] The optical/electrical communication interface 692 can be similar to, e.g., the integrated communication device 210 (FIG. 2), 252 (FIG. 4), 374 (FIG. 11), 382 (FIG. 12), 402 (FIG. 13), 428 (FIG. 14), and 512 (FIG. 32), except that the optical/electrical communication interfaces 692b and 692c are mounted on the side of the circuit board 693b opposite to the side of the data processing chip 691b. In some examples, the optical/electrical communication interface 692 can be similar to the integrated optical communication device 448, 462, 466, 472 (FIG. 17). The optical connector 699 can be similar to, e.g., the first optical connector part 213 (FIGS. 2, 4), the first optical connector 356 (FIGS. 11, 12), the first optical connector 404 (FIGS. 13, 14), the first optical connector part 456 (FIG. 17), and the first optical connector part 520 (FIG. 32). In some examples, the optical connector is not attached vertically to a photonic integrated circuit that is part of the optical/electrical communication interface 692 but rather can be attached in-plane to the photonic integrated circuit using, e.g., V-groove fiber attachments, tapered or un-tapered fiber edge coupling, etc., followed by a mechanism to direct the light interfacing to the photonic integrated circuit to a direction that is substantially perpendicular to the photonic integrated circuit, such as one or more substantially 90-degree turning mirrors, one or more substantially 90-degree bent optical fibers, etc. In some examples, a portion of the optical connector 699 can be part of the optical/electrical communication interface 692. In some examples, the optical connector 699 can also include the second optical connector part 223 (FIGS. 2, 4), 458 (FIG. 17) that is optically coupled to the optical fibers.

[0442] In some examples, the optical/electrical communication interfaces 692 are securely fixed (e.g., by soldering) to the circuit board 693b. In some examples, the optical/electrical communication interfaces 692 are removably connected to the circuit board 693b, e.g., by use of mechanical mechanisms such as one or more snap-on or screw-on mechanisms. An advantage of the system 690b is that in case of a malfunction at one of the optical/electrical communication interfaces 692, the faulty optical/electrical communication interface 692 can be replaced without opening the enclosure 694b.

[0443] FIG. 26C is a top view of an example data processing system 690c in which a data processing chip 691c is mounted near optical/electrical communication interfaces 692d, 692e, 692f (collectively referenced as 692) to enable high bandwidth data paths (e.g., one, ten, or more Gigabits per second per data path) between the data processing chip 691c and each of the optical/electrical communication interfaces 692. The data processing chip 691c is mounted on a first side of a circuit board 693c that functions as a front panel of an enclosure 694c of the system 690c. In this example, the optical/electrical communication interface 692d is mounted on the first side of the circuit board 693c and the optical/electrical communication interfaces 692e and 692f are mounted on a second side of the circuit board 693c, in which the second side faces the exterior of the enclosure 694c. In this example, the optical/electrical communication interfaces 692e and 692f are mounted on an exterior side of the enclosure 694c, allowing connection to optical fibers from the front of the enclosure 694c while the optical/electrical communication interface 692d is located internal to the enclosure 694c, for example, to allow connection to optical fiber at the rear of the enclosure 694c. In some examples, two or more of the optical/electrical communication interfaces 692 can be located internal to the enclosure 694c and connect to optical fibers at the rear of the enclosure 694c.

[0444] The enclosure 694c has side panels 695c and 696c, a rear panel 697c, a top panel, and a bottom panel. In some examples, the circuit board 693c is perpendicular to the bottom panel. In some examples, the circuit board 693c is oriented at an angle in a range −60° to 60° (or −30° to 30°, or −10° to 10°, or −1° to 1°) relative to a vertical direction of the bottom panel.

[0445] Each of the optical/electrical communication interfaces 692 is electrically coupled to the data processing chip 691c by electrical connectors or traces 698c that pass through the circuit board 693c in the thickness direction. For example, the electrical connectors or traces 698c can be configured as vias of the circuit board 693c. In this example, the electrical connectors or traces 698c extend to both sides of the circuit board 693b (e.g., for connecting to optical/electrical communication interfaces 692 located internal to and external of the enclosure 694b. The signal paths between the data processing chip 691c and each of the optical/electrical communication interfaces 692 can be unidirectional or bidirectional, similar to those of the systems 630, 650 and 680.

[0446] For example, the system 690c can be configured such that signals are transmitted unidirectionally between the data processing chip 691c and one of the optical/electrical communication interfaces 692, and bidirectionally between the data processing chip 691c and another one of the optical/electrical communication interfaces 692. For example, the system 690c can be configured such that signals are transmitted unidirectionally from the optical/electrical communication interface 692d to the data processing chip 691c, and unidirectionally from the data processing chip 691c to the optical/electrical communication interface 692e and/or optical/electrical communication interface 692f.

[0447] Optical connectors 699d, 699e, 699f (collectively referenced as 699) are provided to couple optical signals from the optical fibers to the optical/electrical communication interfaces 692d, 692e, 692f, respectively. The optical connectors 699 can be securely fixed, or releasably connected, to the optical/electrical communication interfaces 692, similar to those of the systems 630, 650, and 680. In the illustrated example, the optical/electrical communication interfaces 692d and optical connector 699d are oriented differently compared to the optical/electrical communication interfaces 692a and optical connector 699a of FIG. 26B. Here the orientation change is a counter clockwise rotation of 90 degrees. Other types of orientation changes (e.g., rotations, pitches, tipping, etc.) may be implemented. Position changes (e.g., translations) and other types of location changes may also be employed. In this example, optical connector 699e and optical connector 699f can connect to optical fibers at the front of the enclosure 694c and the optical connector 699d can connect to optical fibers the rear of the enclosure 694c. In the illustrated example, the optical connector 699d connects to an optical fiber at the rear of the enclosure 694c by being connected to a fiber 1000c that connects to a rear panel interface 1001c (e.g., a backplane, etc.) that is mounted to the rear panel 697c.

[0448] The optical/electrical communication interface 692 can be similar to, e.g., the integrated communication device 210 (FIG. 2), 252 (FIG. 4), 374 (FIG. 11), 382 (FIG. 12), 402 (FIG. 13), 428 (FIG. 14), and 512 (FIG. 32), except that the optical/electrical communication interface 692e and 692f are mounted on the side of the circuit board 693c opposite to the side of the data processing chip 691c. In some examples, the optical/electrical communication interface 692 can be similar to the integrated optical communication device 448, 462, 466, 472 (FIG. 17). The optical connector 699 can be similar to, e.g., the first optical connector part 213 (FIGS. 2, 4), the first optical connector 356 (FIGS. 11, 12), the first optical connector 404 (FIGS. 13, 14), the first optical connector part 456 (FIG. 17), and the first optical connector part 520 (FIG. 32). In some examples, the optical connector is not attached vertically to a photonic integrated circuit that is part of the optical/electrical communication interface 692 but rather can be attached in-plane to the photonic integrated circuit using, e.g., V-groove fiber attachments, tapered or un-tapered fiber edge coupling, etc., followed by a mechanism to direct the light interfacing to the photonic integrated circuit to a direction that is substantially perpendicular to the photonic integrated circuit, such as one or more substantially 90-degree turning mirrors, one or more substantially 90-degree bent optical fibers, etc. In some examples, a portion of the optical connector 699 can be part of the optical/electrical communication interface 692. In some examples, the optical connector 699 can also include the second optical connector part 223 (FIGS. 2, 4), 458 (FIG. 17) that is optically coupled to the optical fibers.

[0449] In some examples, the optical/electrical communication interfaces 692 are securely fixed (e.g., by soldering) to the circuit board 693c. In some examples, the optical/electrical communication interfaces 692 are removably connected to the circuit board 693c, e.g., by use of mechanical mechanisms such as one or more snap-on or screw-on mechanisms. An advantage of the system 690c is that in case of a malfunction at one of the optical/electrical communication interfaces 692, the faulty optical/electrical communication interface 692 can be replaced without opening the enclosure 694c.

[0450] FIG. 27 is a top view of an example data processing system 700 in which a data processing chip 702 is mounted near optical/electrical communication interfaces 704a, 704b, 704c (collectively referenced as 704) to enable high bandwidth data paths (e.g., one, ten, or more Gigabits per second per data path) between the data processing chip 702 and each of the optical/electrical communication interfaces 704. The data processing chip 702 is mounted on a first side of a circuit board 706 that is positioned near a front panel of an enclosure 710 of the system 700, similar to the configuration of the system 650 (FIG. 25). In some examples, the data processing chip 702 is mounted on a substrate (e.g., a ceramic substrate), and the substrate is attached to the circuit board 706. The optical/electrical communication interfaces 704 are mounted on a second side of the circuit board 708. In this example, the optical/electrical communication interfaces 704 pass through openings in the front panel 708, allowing optical fibers to be easily coupled to the optical/electrical communication interfaces 704.

[0451] The enclosure 710 has side panels 712 and 714, a rear panel 716, a top panel, and a bottom panel. In some examples, the circuit board 706 and the front panel 708 are oriented at an angle in a range −60° to 60° relative to a vertical direction of the bottom panel. In some examples, the circuit board 706 is substantially parallel to the front panel 708, e.g., the angle between the surface of the circuit board 706 and the surface of the front panel 708 can be in a range of −5° to 5°. In some examples, the circuit board 706 is at an angle relative to the front panel 708, in which the angle is in a range of −45° to 45°.

[0452] For example, the angle can refer to a rotation around an axis that is parallel to the larger dimension of the front panel (e.g., the width dimension in a typical 1U, 2U, or 4U rackmount device), or a rotation around an axis that is parallel to the shorter dimension of the front panel (e.g., the height dimension in the 1U, 2U, or 4U rackmount device). The angle can also refer to a rotation around an axis along any other direction. For example, the circuit board 706 is positioned relative to the front panel such that components such as the interconnection modules, including optical modules or photonic integrated circuits, mounted on or attached to the circuit board 706 can be accessed through the front side, either through one or more openings in the front panel, or by opening the front panel to expose the components, without the need to separate the top or side panels from the bottom panel. Such orientation of the circuit board (or a substrate on which a data processing module is mounted) relative to the front panel also applies to the examples shown in FIGS. 21 to 26, 28B to 29B, 69A, 70, 71A, 72, 72A, 74A, 75A, 75C, 76, 77A, 77B, 78, 96 to 98, 100, 110, 112, 113, 115, 117 to 122, 125A to 127, 129, 136 to 149, 159, and 160.

[0453] Each of the optical/electrical communication interfaces 704 is electrically coupled to the data processing chip 702 by electrical connectors or traces 718 that pass through the circuit board 706 in the thickness direction, similar to those of the system 680 (FIG. 26). The signal paths between the data processing chip 702 and each of the optical/electrical communication interfaces 704 can be unidirectional or bidirectional, similar to those of the system 630 (FIG. 24), 650 (FIG. 25), and 680 (FIG. 26).

[0454] Optical connectors 716a, 716b, 716c (collectively referenced as 716) are provided to couple optical signals from the optical fibers to the optical/electrical communication interfaces 704a, 704b, 704c, respectively. The optical connectors 716 can be securely fixed, or releasably connected, to the optical/electrical communication interfaces 704, similar to those of the systems 630, 650, and 680.

[0455] The optical/electrical communication interface 704 can be similar to, e.g., the integrated communication device 210 (FIG. 2), 252 (FIG. 4), 374 (FIG. 11), 382 (FIG. 12), 402 (FIG. 13), 428 (FIG. 14), and 512 (FIG. 32), except that the optical/electrical communication interface 704 is mounted on the side of the circuit board 706 opposite to the side of the data processing chip 702. In some examples, the optical/electrical communication interface 704 can be similar to the integrated optical communication device 448, 462, 466, 472 (FIG. 17). The optical connector 716 can be similar to, e.g., the first optical connector part 213 (FIGS. 2, 4), the first optical connector 356 (FIGS. 11, 12), the first optical connector 404 (FIGS. 13, 14), the first optical connector part 456 (FIG. 17), and the first optical connector part 520 (FIG. 32). In some examples, the optical connector is not attached vertically to a photonic integrated circuit that is part of the optical/electrical communication interface 704 but rather can be attached in-plane to the photonic integrated circuit using, e.g., V-groove fiber attachments, tapered or un-tapered fiber edge coupling, etc., followed by a mechanism to direct the light interfacing to the photonic integrated circuit to a direction that is substantially perpendicular to the photonic integrated circuit, such as one or more substantially 90-degree turning mirrors, one or more substantially 90-degree bent optical fibers, etc. In some examples, a portion of the optical connector 716 can be part of the optical/electrical communication interface 704. In some examples, the optical connector 716 can also include the second optical connector part 223 (FIGS. 2, 4), 458 (FIG. 17) that is optically coupled to the optical fibers.

[0456] In some examples, the optical/electrical communication interfaces 704 are securely fixed (e.g., by soldering) to the circuit board 706. In some examples, the optical/electrical communication interfaces 704 are removably connected to the circuit board 706, e.g., by use of mechanical mechanisms such as one or more snap-on or screw-on mechanisms. An advantage of the system 700 is that in case of a malfunction at one of the optical/electrical communication interfaces 704, the faulty optical/electrical communication interface 704 can unplugged or decoupled from the circuit board 706 and replaced without opening the enclosure 710.

[0457] In some implementations, the optical/electrical communication interfaces 704 do not protrude through openings in the front panel 708. For example, each optical/electrical communication interface 704 can be at a distance behind the front panel 708, and a fiber patchcord or pigtail can connect the optical/electrical communication interface 704 to an optical connector on the front panel 708, similar to the examples shown in FIGS. 77A, 77B, 78, 125A, 125B, 129, and 159. In some examples, the front panel 708 is configured to be removable or to be able to open to allow servicing of communication interface 704, similar to the examples shown in FIGS. 77A, 125A, and 159.

[0458] FIG. 28A is a top view of an example data processing system 720 in which a data processing chip 722 is mounted near an optical/electrical communication interface 724 to enable high bandwidth data paths (e.g., one, ten, or more Gigabits per second per data path) between the data processing chip 720 and the optical/electrical communication interface 724. The data processing chip 722 is mounted on a first side of a circuit board 730 that functions as a front panel of an enclosure 732 of the system 720. In some examples, the data processing chip 722 is mounted on a substrate (e.g., a ceramic substrate), and the substrate is attached to the circuit board 730. The optical/electrical communication interface 724 is mounted on a second side of the circuit board 730, in which the second side faces the exterior of the enclosure 732. In this example, the optical/electrical communication interface 724 is mounted on an exterior side of the enclosure 732, allowing optical fibers 734 to be easily coupled to the optical/electrical communication interface 724.

[0459] The enclosure 732 has side panels 736 and 738, a rear panel 740, a top panel, and a bottom panel. In some examples, the circuit board 730 is perpendicular to the bottom panel. In some examples, the circuit board 730 is oriented at an angle in a range −60° to 60° relative to a vertical direction of the bottom panel.

[0460] The optical/electrical communication interface 724 includes a photonic integrated circuit 726 mounted on a substrate 728 that is electrically coupled to the circuit board 730. The optical//electrical communication interface 724 is electrically coupled to the data processing chip 722 by electrical connectors or traces 742 that pass through the circuit board 730 in the thickness direction. For example, the electrical connectors or traces 742 can be configured as vias of the circuit board 730. The signal paths between the data processing chip 722 and the optical/electrical communication interface 724 can be unidirectional or bidirectional, similar to those of the systems 630, 650, 680, and 700.

[0461] An optical connector 744 is provided to couple optical signals from the optical fibers 734 to the optical/electrical communication interface 724. The optical connector 744 can be securely fixed, or removably connected, to the optical/electrical communication interface 744, similar to those of the systems 630, 650, 680, and 700.

[0462] In some implementations, the optical/electrical communication interface 724 can be similar to, e.g., the integrated communication device 448, 462, 466, and 472 of FIG. 17. The optical signals from the optical fibers are processed by the photonic integrated circuit 726, which generates serial electrical signals based on the optical signals. For example, the serial electrical signals are amplified by a set of transimpedance amplifiers and drivers (which can be part of the photonic integrated circuit 726 or a serializers/deserializers module in the data processing chip 722), which drives the output signals that are transmitted to the serializers/deserializers module embedded in the data processing chip 722.

[0463] The optical connector 744 includes a first optical connector 746 and a second optical connector 748, in which the second optical connector 748 is optically coupled to the optical fibers 734. The first optical connector 746 can be similar to, e.g., the first optical connector part 213 (FIGS. 2, 4), the first optical connector 356 (FIGS. 11, 12), the first optical connector 404 (FIGS. 13, 14), the first optical connector part 456 (FIG. 17), and the first optical connector part 520 (FIG. 32). The second optical connector 748 can be similar to the second optical connector part 223 (FIGS. 2, 4) and 458 (FIG. 17). In some examples, the optical connectors 746 and 748 can form a single piece such that the optical/electrical communication interface 724 is securely or fixedly attached to a fiber bundle. In some examples, the optical connector is not attached vertically to the photonic integrated circuit 726 but rather can be attached in-plane to the photonic integrated circuit using, e.g., V-groove fiber attachments, tapered or un-tapered fiber edge coupling, etc., followed by a mechanism to direct the light interfacing to the photonic integrated circuit to a direction that is substantially perpendicular to the photonic integrated circuit, such as one or more substantially 90-degree turning mirrors, one or more substantially 90-degree bent optical fibers, etc.

[0464] In some examples, the optical/electrical communication interface 724 is securely fixed (e.g., by soldering) to the circuit board 730. In some examples, the optical/electrical communication interface 724 is removably connected to the circuit board 730, e.g., by use of mechanical mechanisms such as one or more snap-on or screw-on mechanisms. An advantage of the system 720 is that in case of a malfunction of the optical/electrical communication interface 724, the faulty optical/electrical communication interface 724 can be replaced without opening the enclosure 732.

[0465] FIG. 28B is a top view of an example data processing system 2800 that is similar to the system 720 of FIG. 28A, except that the circuit board 730 that is recessed from a front panel 2802 of an enclosure 732 of the system 2800. The photonic integrated circuit 726 is optically coupled through a fiber patchcord or pigtail 2804 to a first optical connector 2806 attached to the inner side of the front panel 2802. The first optical connector 2806 is optically coupled to a second optical connector 2808 attached to the outer side of the front panel 2802. The second optical connector 2808 is optically coupled to the exterior optical fibers 734.

[0466] The technique of using a fiber patchcord or pigtail to optically couple the photonic integrated circuit to the optical connector attached to the inner side of the front panel can also be applied to the data processing system 700 of FIG. 27. For example, the modified system can have a recessed substrate or circuit board, multiple co-packaged optical modules (e.g., 704) mounted on the opposite side of the data processing chip 702 relative to the substrate or circuit board, and fiber jumpers (e.g., 2804) optically coupling the co-packaged optical modules to the front panel.

[0467] In the examples of FIGS. 28A and 28B, the data processing chip 722 can be mounted on a substrate that is electrically coupled to the circuit board 730, similar to the example shown in FIG. 150.

[0468] In each of the examples in FIGS. 24, 25, 26, 27, and 28, the optical/electrical communication interface 644, 652, 684, 704, and 724 can be electrically coupled to the circuit board 642, 654, 686, 706, and 730, respectively, using electrical contacts that include one or more of spring-loaded elements, compression interposers, and/or land-grid arrays.

[0469] FIG. 29A is a diagram of an example data processing system 750 that includes a vertically mounted circuit board 752 that enables high bandwidth data paths (e.g., one, ten, or more Gigabits per second per data path) between data processing chips 758 and optical/electrical communication interfaces 760. The data processing chips 758 and the optical/electrical communication interfaces 760 are mounted on the circuit board 752, in which each data processing chip 758 is electrically coupled to a corresponding optical/electrical communication interface 760. The data processing chips 758 are electrically coupled to one another by electrical connectors (e.g., electrical signal lines on one or more layers of the circuit board 752).

[0470] The data processing chips 758 can be similar to, e.g., the electronic processor integrated circuit, data processing chip, or host application specific integrated circuit 240 (FIGS. 2, 4, 6, 7, 11, 12), digital application specific integrated circuit 444 (FIG. 17), data processor 502 (FIG. 20), data processing chip 572 (FIGS. 22, 23), 640 (FIG. 24), 670 (FIG. 25), 682 (FIG. 26), 702 (FIG. 27), and 722 (FIG. 28). Each of the data processing chips 758 can be, e.g., a network switch, a central processor unit, a graphics processor unit, a tensor processing unit, a neural network processor, an artificial intelligence accelerator, a digital signal processor, a microcontroller, or an application specific integrated circuit (ASIC).

[0471] Although the figure shows that the optical/electrical communication interfaces 760 are mounted on the side of the circuit board 752 facing the front panel 754, the optical/electrical communication interfaces 760 can also be mounted on the side of the circuit board 752 facing the interior of the enclosure 756. The optical/electrical communication interfaces 760 can be similar to, e.g., the integrated communication devices 210 (FIGS. 2, 3, 10), 252 (FIGS. 4, 5), 262 (FIG. 6), the integrated optical communication devices 282 (FIGS. 7-9), 374 (FIG. 11), 382 (FIG. 12), 390 (FIG. 13), 428 (FIG. 14), 402 (FIGS. 15, 16), 448, 462, 466, 472 (FIG. 17), the integrated communication devices 574 (FIG. 22), 612 (FIG. 23), and the optical/electrical communication interfaces 644 (FIG. 24), 652 (FIG. 25), 684 (FIG. 26), 704 (FIG. 27).

[0472] The circuit board 752 is positioned near a front panel 754 of an enclosure 756, and optical signals are coupled to the optical/electrical communication interfaces 760 through optical paths that pass through openings in the front panel 754. This allows users to conveniently removably connect optical fiber cables 762 to the input/output interfaces 760. The position and orientation of the circuit board 752 relative to the enclosure 756 can be similar to, e.g., those of the circuit board 654 (FIG. 25) and 706 (FIG. 27).

[0473] In some implementations, the data processing system 750 can include multiple types of optical/electrical communication interfaces 760. For example, some of the optical/electrical communication interfaces 760 can be mounted on the same side of the circuit board 752 as the corresponding data processing chip 758, and some of the optical/electrical communication interfaces 760 can be mounted on the opposite side of the circuit board 752 as the corresponding data processing chip 758. Some of the optical/electrical communication interfaces 760 can include first and second serializers/deserializers modules, and the corresponding data processing chips 758 can include third serializers/deserializers modules, similar to the examples in FIGS. 2-8, 11-14, 20, 22, and 23. Some of the optical/electrical communication interfaces 760 can include no serializers/deserializers module, and the corresponding data processing chips 758 can include serializers/deserializers modules, similar to the example of FIG. 17. Some of the optical/electrical communication interfaces 760 can include sets of transimpedance amplifiers and drivers, either embedded in the photonic integrated circuits or in separate chips external to the photonic integrated circuits. Some of the optical/electrical communication interfaces 760 do not include transimpedance amplifiers and drivers, in which sets of transimpedance amplifiers and drivers are included in the corresponding data processing chips 758. The data processing system 750 can also include electrical communication interfaces that interface to electrical cables, such as high speed PCIe cables, Ethernet cables, or Thunderbolt™ cables. The electrical communication interfaces can include modules that perform various functions, such as translation of communication protocols and/or conditioning of signals.

[0474] Other types of connections may be present and associated with circuit board 752 and other boards included in the enclosure 756. For example, two or more circuit boards (e.g., vertically mounted circuit boards) can be connected which may or may not include the circuit board 752. For instances in which circuit board 752 is connected to at least one other circuit board (e.g., vertically mounted in the enclosure 756), one or more connection techniques can be employed. For example, an optical/electrical communication interface (e.g., similar to optical/electrical communication interfaces 760) can be used to connect data processing chips 758 to other circuit boards. Interfaces for such connections can be located on the same side of the circuit board 752 that the processing chips 758 are mounted. In some implementations, interfaces can be located on another portion of the circuit board (e.g., a side that is opposite from the side that the processing chips 758 are mounted). Connections can utilize other portions of the circuit board 752 and/or one or more other circuit boards present in the enclosure 756. For example an interface can be located on an edge of one or more of the boards (e.g., an upper edge of a vertically mounted circuit board) and the interface can connect with one or more other interfaces (e.g., the optical/electrical communication interfaces 760, another edge mounted interface, etc.). Through such connections, two or more circuit boards can connect, receive and send signals, etc.

[0475] In the example shown in FIG. 29A, the circuit board 752 is placed near the front panel 754. In some examples, the circuit board 752 can also function as the front panel, similar to the examples in FIGS. 22-24, 26, and 28.

[0476] FIG. 29B is a diagram of an example data processing system 2000 that illustrates some of the configurations described with respect to FIGS. 26A to 26C and FIG. 29A along with other capabilities. The system 2000 includes a vertically mounted printed circuit board 2002 (or, e.g., a substrate) upon which is mounted a data processing chip 2004 (e.g., an ASIC), and a heat sink 2006 is thermally coupled to the data processing chip 2004. Optical/electrical communication interfaces are mounted on both sides of the printed circuit board 2002. In particular, optical/electrical communication interface 2008 is mounted on the same side of the printed circuit board 2002 as the data processing chip 2004. In this example, optical/electrical communication interfaces 2010, 2012, and 2014 are mounted on an opposite side of the printed circuit board 2002. To send and receive signals (e.g., with other optical/electrical communication interfaces), each of the optical/electrical communication interfaces 2010, 2012, and 2014 connects to optical fibers 2016, 2018, 2020, respectively. Electrical connection sockets/connectors can also be mounted to one or more sides of the printed circuit board 2002 for sending and receiving electrical signals, for example. In this example, two electrical connection sockets/connectors 2022 and 2024 are mounted to the side of the printed circuit board 2002 that the data processing chip 2004 is mounted and two electrical connection sockets/connectors 2026 and 2028 are mounted to the opposite side of the printed circuit board 2002. In this example, electrical connection sockets/connector 2028 is connected (or includes) a timing module 2030 that provides various functionality (e.g., regenerate data, retime data, maintain signal integrity, etc.). To send and receive electrical signals, each of the electrical connection sockets/connectors 2022-2028 are connected to electrical connection cables 2032, 2034, 2036, 2038, respectively. One or more types of connection cables can be implemented, for example, fly-over cables can be employed for connecting to one or more of the electrical connection sockets/connectors 2022-2028.

[0477] In this example, the system 2000 includes vertically mounted line cards 2040, 2042, 2044. In this particular example, line card 2040 includes an electrical connection sockets/connector 2046 that is connected to electrical cable 2036, and line card 2042 includes an electrical connection sockets/connector 2048 that is connected to electrical cable 2032. Line card 2044 includes an electrical connection sockets/connector 2050. Each of the line cards 2040, 2042, 2044 include pluggable optical modules 2052, 2054, 2056 that can implement various interface techniques (e.g., QSFP, QSFP-DD, XFP, SFP, CFP).

[0478] In this particular example, the printed circuit board 2002 is approximate to a forward panel 2058 of the system 2000; however, the printed circuit board 2002 can be positioned in other locations within the system 2000. Multiple printed circuit boards can also be included in the system 2000. For example, a second printed circuit board 2060 (e.g., a backplane) is included in the system 2000 and is located approximate to a back panel 2062. By locating the printed circuit board 2060 towards the rear, signals (e.g., data signals) can be sent to and received from other systems (e.g., another switch box) located, for example, in the same switch rack or other location as the system 2000. In this example, a data processing chip 2064 is mounted to the printed circuit board 2060 that can perform various operations (e.g., data processing, prepare data for transmission, etc.). Similar to the printed circuit board 2002 located forward in the system 2000, the printed circuit board 2060 includes an optical/electrical communication interface 2066 that communicates with the optical/electrical communication interface 2008 (located on the same side on printed circuit board 2002 as data processing chip 2004) using optical fibers 2068. The printed circuit board 2060 includes electrical connection sockets/connectors 2070 that uses the electrical connection cable 2034 to send electrical signals to and receive electrical signals from the electrical connection sockets/connectors 2024. The printed circuit board 2060 can also communicate with other components of the system 2000, for example, one or more of the line cards. As illustrated in the figure, electrical connection sockets/connectors 2072 located on the printed circuit board 2060 uses the electrical connection cable 2074 to send electrical signals to and/or receive electrical signals from the electrical connection sockets/connector 2050 of the line card 2044. Similar to the printed circuit board 2002, other portions of the system 2000 can include timing modules. For example, the line cards 2040, 2042, and 2044 can include timing modules (respectively identified with symbol “*”, “**”, and “***”). Similarly, the second circuit board 2060 can include timing modules such as timing modules 2076 and 2078 for regenerating data, re-timing data, maintaining signal integrity, etc.

[0479] A feature of some of the systems described in this document is that the main data processing module(s) of a system, such as switch chip(s) in a switch server, and the communication interface modules that support the main data processing module(s), are configured to allow convenient access by users. In the examples shown in FIGS. 21 to 29B, 69A, 70, 71A, 72, 72A, 74A, 75A, 75C, 76, 77A, 77B, 78, 96 to 98, 100, 110, 112, 113, 115, 117 to 122, 125A to 127, 129, 136 to 149, 159, and 160, the main data processing module and the communication interface modules are positioned near the front panel, the rear panel, or both, and allow easy access by the user through the front/rear panel. However, it is also possible to position the main data processing module and the communication interface modules near one or more side panels, the top panel, the bottom panel, or two or more of the above, depending on how the system is placed in the environment. In a system that includes multiple racks of rackmount devices (see e.g., FIGS. 76 and 86), the communication interfaces (e.g., co-packaged optical modules) in each rackmount device can be conveniently accessed without the need to remove the rackmount device from the rack and opening up the housing in order to expose the inner components.

[0480] In some implementations, for a single rack of rackmount servers where there is open space at the front, rear, left, and right side of the rack, in each rackmount server, it is possible to place a first main data processing module and the communication interface modules supporting the first main data processing module near the front panel, place a second main data processing module and the communication interface modules supporting the second main data processing module near the left panel, place a third main data processing module and the communication interface modules supporting the third main data processing module near the right panel, and place a fourth main data processing module and the communication interface modules supporting the fourth main data processing module near the rear panel. The thermal solutions, including the placement of fans and heat dissipating devices, and the configuration of airflows around the main data processing modules and the communication interface modules, are adjusted accordingly.

[0481] For example, if a data processing server is mounted to the ceiling of a room or a vehicle, the main data processing module and the communication interface modules can be positioned near the bottom panel for easy access. For example, if a data processing server is mounted beneath the floor panel of a room or a vehicle, the main data processing module and the communication interface modules can be positioned near the top panel for easy access. The housing of the data processing system does not have to be in a box shape. For example, the housing can have curved walls, be shaped like a globe, or have an arbitrary three-dimensional shape.

[0482] FIG. 30 is a diagram of an example high bandwidth data processing system 800 that can be similar to, e.g., systems 200 (FIGS. 2, 20), 250 (FIG. 4), 260 (FIG. 6), 280 (FIG. 7), 350 (FIG. 11), 380 (FIG. 12), 390 (FIG. 13), 420 (FIG. 14), 560 (FIG. 22), 600 (FIG. 23), 630 (FIG. 24), and 650 (FIG. 25) described above. A first optical signal 770 is transmitted from an optical fiber to a photonic integrated circuit 772, which generates a first serial electrical signal 774 based on the first optical signal. The first serial electrical signal 774 is provided to a first serializers/deserializers module 776, which converts the first serial electrical signal 774 to a third set of parallel signals 778. The first serializers/deserializers module 776 conditions the serial electrical signal upon conversion into the parallel electrical signals, in which the signal conditioning can include, e.g., one or more of clock and data recovery, and signal equalization. The third set of parallel signals 778 is provided to a second serializers/deserializers module 780, which generates a fifth serial electrical signal 782 based on the third set of parallel signals 778. The fifth serial electrical signal 782 is provided to a third serializers/deserializers module 784, which generates a seventh set of parallel signals 786 that is provided to a data processor 788.

[0483] In some implementations, the photonic integrated circuit 772, the first serializers/deserializers module 776, and the second serializers/deserializers module 780 can be mounted on a substrate of an integrated communication device, an optical/electrical communication interface, or an input/output interface module. The first serializers/deserializers module 776 and the second serializers/deserializers module 780 can be implemented in a single chip. In some implementations, the third serializers/deserializers module 784 can be embedded in the data processor 788, or the third serializers/deserializers module 784 can be separate from the data processor 788.

[0484] The data processor 788 generates an eighth set of parallel signals 790 that is sent to the third serializers/deserializers module 784, which generates a sixth serial electrical signal 792 based on the eighth set of parallel signals 790. The sixth serial electrical signal 792 is provided to the second serializers/deserializers module 780, which generates a fourth set of parallel signals 794 based on the sixth serial electrical signal 792. The second serializers/deserializers module 780 can condition the serial electrical signal 792 upon conversion into the fourth set of parallel electrical signals 794. The fourth set of parallel signals 794 is provided to the first serializers/deserializers module 780, which generates a second serial electrical signal 796 based on the fourth set of parallel signals 794 that is sent to the photonic integrated circuit 772. The photonic integrated circuit 772 generates a second optical signal 798 based on the second serial electrical signal 796, and sends the second optical signal 798 to an optical fiber. The first and second optical signals 770, 798 can travel on the same optical fiber or on different optical fibers.

[0485] A feature of the system 800 is that the electrical signal paths traveled by the first, fifth, sixth, and second serial electrical signals 774, 782, 792, 796 are short (e.g., less than 5 inches), to allow the first, fifth, sixth, and second serial electrical signals 782, 792 to have a high data rate (e.g., up to 50 Gbps).

[0486] FIG. 31 is a diagram of an example high bandwidth data processing system 810 that can be similar to, e.g., systems 680 (FIG. 26), 700 (FIG. 27), and 750 (FIG. 29) described above. The system 810 includes a data processor 812 that receives and sends signals from and to multiple photonic integrated circuits. The system 810 includes a second photonic integrated circuit 814, a fourth serializers/deserializers module 816, a fifth serializers/deserializers module 818, and a sixth serializers/deserializers module 820. The operations of the second photonic integrated circuit 814, a fourth serializers/deserializers module 816, a fifth serializers/deserializers module 818, and a sixth serializers/deserializers module 820 can be similar to those of the first photonic integrated circuit 772, the first serializers/deserializers module 776, the second serializers/deserializers module 780, and the third serializers/deserializers module 784. The third serializers/deserializers module 784 and the sixth serializers/deserializers module 820 can be embedded in the data processor 812, or be implemented in separate chips.

[0487] In some examples, the data processor 812 processes first data carried in the first optical signal received at the first photonic integrated circuit 772, and generates second data that is carried in the fourth optical signal output from the second photonic integrated circuit 814.

[0488] The examples in FIGS. 30 and 31 include three serializers/deserializers modules between the photonic integrated circuit and the data processor, it is understood that the same principles can be applied to systems that has only one serializers/deserializers module between the photonic integrated circuit and the data processor.

[0489] In some implementations, signals are transmitted unidirectionally from the photonic integrated circuit 772 to the data processor 788 (FIG. 30). In that case, the first serializers/deserializers module 776 can be replaced with a serial-to-parallel converter, the second serializers/deserializers module 780 can be replaced with a parallel-to-serial converter, and the third serializers/deserializers module 784 can be replaced with a serial-to-parallel converter. In some implementations, signals are transmitted unidirectionally from the data processor 812 (FIG. 31) to the second photonic integrated circuit 814. In that case, the sixth serializers/deserializers module 820 can be replaced with a parallel-to-serial converter, the fifth serializers/deserializers module 818 can be replaced with a serial-to-parallel converter, and the fourth serializers/deserializers module 816 can be replaced with a parallel-to-serial converter.

[0490] It should be appreciated by those of ordinary skill in the art that the various embodiments described herein in the context of coupling light from one or more optical fibers, e.g., 226 (FIGS. 2 and 4) or 272 (FIGS. 6 and 7) to the photonic integrated circuit, e.g., 214 (FIGS. 2 and 4), 264 (FIG. 6), or 296 (FIG. 7) will be equally operable to couple light from the photonic integrated circuit to one or more optical fibers. This reversibility of the coupling direction is a general feature of at least some embodiments described herein, including some of those using polarization diversity.

[0491] The example optical systems disclosed herein should only be viewed as some of many possible embodiments that can be used to perform polarization demultiplexing and independent array pattern scaling, array geometry re-arrangement, spot size scaling, and angle-of-incidence adaptation using diffractive, refractive, reflective, and polarization-dependent optical elements, 3D waveguides and 3D printed optical components. Other implementations achieving the same set of functionalities are also covered by the spirit of this disclosure.

[0492] For example, the optical fibers can be coupled to the edges of the photonic integrated circuits, e.g., using fiber edge couplers. The signal conditioning (e.g., clock and data recovery, signal equalization, or coding) can be performed on the serial signals, the parallel signals, or both. The signal conditioning can also be performed during the transition from serial to parallel signals.

[0493] In some implementations, the data processing systems described above can be used in, e.g., data center switching systems, supercomputers, internet protocol (IP) routers, Ethernet switching systems, graphics processing work stations, and systems that apply artificial intelligence algorithms.

[0494] In the examples described above in which the figures show a first serializers/deserializers module (e.g., 216) placed adjacent to a second serializers/deserializers module (e.g., 217), it is understood that a bus processing unit 218 can be positioned between the first and second serializers/deserializers modules and perform, e.g., switching, re-routing, and/or coding functions described above.

[0495] In some implementations, the data processing systems described above includes multiple data generators that generate large amounts of data that are sent through optical fibers to the data processors for processing. For example, an autonomous driving vehicle (e.g., car, truck, train, boat, ship, submarine, helicopter, drone, airplane, space rover, or space ship) or a robot (e.g., an industrial robot, a helper robot, a medical surgery robot, a merchandise delivery robot, a teaching robot, a cleaning robot, a cooking robot, a construction robot, an entertainment robot) can include multiple high resolution cameras and other sensors (e.g., LIDARs (Light Detection and Ranging), radars) that generate video and other data that have a high data rate. The cameras and/or sensors can send the video data and/or sensor data to one or more data processing modules through optical fibers. The one or more data processing modules can apply artificial intelligence technology (e.g., using one or more neural networks) to recognize individual objects, collections of objects, scenes, individual sounds, collections of sounds, and/or situations in the environment of the vehicle and quickly determine appropriate actions for controlling the vehicle or robot.

[0496] FIG. 34 is a flow diagram of an example process for processing high bandwidth data. A process 830 includes receiving 832 a plurality of channels of first optical signals from a plurality of optical fibers. The process 830 includes generating 834 a plurality of first serial electrical signals based on the received optical signals, in which each first serial electrical signal is generated based on one of the channels of first optical signals. The process 830 includes generating 836 a plurality of sets of first parallel electrical signals based on the plurality of first serial electrical signals, and conditioning the electrical signals, in which each set of first parallel electrical signals is generated based on a corresponding first serial electrical signal. The process 830 includes generating 838 a plurality of second serial electrical signals based on the plurality of sets of first parallel electrical signals, in which each second serial electrical signal is generated based on a corresponding set of first parallel electrical signals.

[0497] In some implementations, a data center includes multiple systems, in which each system incorporates the techniques disclosed in FIGS. 22 to 29 and the corresponding description. Each system includes a vertically mounted printed circuit board, e.g., 570 (FIG. 22), 610 (FIG. 23), 642 (FIG. 24), 654 (FIG. 25), 686 (FIG. 26), 706 (FIG. 27), 730 (FIG. 28), 752 (FIG. 29) that functions as the front panel of the housing or is substantially parallel to the front panel. At least one data processing chip and at least one integrated communication device or optical/electrical communication interface are mounted on the printed circuit board. The integrated communication device or optical/electrical communication interface can incorporate techniques disclosed in FIGS. 2-22 and 30-34 and the corresponding description. Each integrated communication device or optical/electrical communication interface includes a photonic integrated circuit that receives optical signals and generates electrical signals based on the optical signals. The optical signals are provided to the photonic integrated circuit through one or more optical paths (or spatial paths) that are provided by, e.g., cores of the fiber-optic cables, which can incorporate techniques described in U.S. patent application Ser. No. 16/822,103. A large number of parallel optical paths (or spatial paths) can be arranged in two-dimensional arrays using connector structures, which can incorporate techniques described in U.S. patent application Ser. No. 16/816,171.

[0498] FIG. 35A shows an optical communications system 1250 providing high-speed communications between a first chip 1252 and a second chip 1254 using co-packaged optical (CPO) interconnect modules 1258 similar to those shown in, e.g., FIGS. 2-5 and 17. Each of the first and second chips 1252, 1254 can be a high-capacity chip, e.g., a high bandwidth Ethernet switch chip. The first and second chips 1252, 1254 communicate with each other through an optical fiber interconnection cable 1734 that includes a plurality of optical fibers. In some implementations, the optical fiber interconnection cable 1734 can include optical fiber cores that transmit data and control signals between the first and second chips 802, 804. The optical fiber interconnection cable 1734 also includes one or more optical fiber cores that transmit optical power supply light from an optical power supply or photon supply to photonic integrated circuits that provide optoelectronic interfaces for the first and second chips 1252, 1254. The optical fiber interconnection cable 1734 can include single-core fibers or multi-core fibers. Each single-core fiber includes a cladding and a core, typically made from glasses of different refractive indices such that the refractive index of the cladding is lower than the refractive index of the core to establish a dielectric optical waveguide. Each multi-core optical fiber includes a cladding and multiple cores, typically made from glasses of different refractive indices such that the refractive index of the cladding is lower than the refractive index of the core. More complex refractive index profiles, such as index trenches, multi-index profiles, or gradually changing refractive index profiles can also be used. More complex geometric structures such as non-circular cores or claddings, photonic crystal structures, photonic bandgap structures, or nested antiresonant nodeless hollow core structures can also be used.

[0499] The example of FIG. 35A illustrates a switch-to-switch use case. An external optical power supply or photon supply 1256 provides optical power supply signals, which can be, e.g., continuous-wave light, one or more trains of periodic optical pulses, or one or more trains of non-periodic optical pulses. The power supply light is provided from the photon supply 1256 to the co-packaged optical interconnect modules 1258 through optical fibers 1730 and 1732, respectively. For example, the optical power supply 1256 can provide continuous wave light, or both pulsed light for data modulation and synchronization, as described in U.S. patent application Ser. No. 16/847,705. This allows the first chip 1252 to be synchronized with the second chip 1254.

[0500] For example, the photon supply 1256 can correspond to the optical power supply 103 of FIG. 1. The pulsed light from the photon supply 1256 can be provided to the link 102_6 of the data processing system 200 of FIG. 20. In some implementations, the photon supply 1256 can provide a sequence of optical frame templates, in which each of the optical frame templates includes a respective frame header and a respective frame body, and the frame body includes a respective optical pulse train. The modulators 417 can load data into the respective frame bodies to convert the sequence of optical frame templates into a corresponding sequence of loaded optical frames that are output through optical fiber link 102_1.

[0501] The implementation shown in FIG. 35A uses a packaging solution corresponding to FIG. 35B, whereby in contrast to FIG. 17 substrates 454 and 460 are not used and the photonic integrated circuit 464 is directly attached to the serializers/deserializers module 446. FIG. 35C shows an implementation similar to FIG. 5, in which the photonic integrated circuit 464 is directly attached to the serializers/deserializers 216.

[0502] FIG. 36 shows an example of an optical communications system 1260 providing high-speed communications between a high-capacity chip 1262 (e.g., an Ethernet switch chip) and multiple lower-capacity chips 1264a, 1264b, 1264c, e.g., multiple network interface cards (NICs) attached to computer servers) using co-packaged optical interconnect modules 1258 similar to those shown in FIG. 35A. The high-capacity chip 1262 communicates with the lower-capacity chips 1264a, 1264b, 1264c through a high-capacity optical fiber interconnection cable 1740 that later branches out into several lower-capacity optical fiber interconnection cables 1742a, 1742b, 1742c that are connected to the lower-capacity chips 1264a, 1264b, 1264c, respectively. This example illustrates a switch-to-servers use case.

[0503] An external optical power supply or photon supply 1266 provides optical power supply signals, which can be continuous-wave light, one or more trains of periodic optical pulses, or one or more trains of non-periodic optical pulses. The power supply light is provided from the photon supply 1266 to the optical interconnect modules 1258 through optical fibers 1744, 1746a, 1746b, 1746c, respectively. For example, the optical power supply 1266 can provide both pulsed light for data modulation and synchronization, as described in U.S. patent application Ser. No. 16/847,705. This allows the high-capacity chip 1262 to be synchronized with the lower-capacity chips 1264a, 1264b, and 1264c.

[0504] FIG. 37 shows an optical communications system 1270 providing high-speed communications between a high-capacity chip 1262 (e.g., an Ethernet switch chip) and multiple lower-capacity chips (1264a, 1264b, e.g., multiple network interface cards (NICs) attached to computer servers) using a mix of co-packaged optical interconnect modules 1258 similar to those shown in FIG. 35 as well as conventional pluggable optical interconnect modules 1272.

[0505] An external optical power supply or photon supply 1274 provides optical power supply signals, which can be continuous-wave light, one or more trains of periodic optical pulses, or one or more trains of non-periodic optical pulses. For example, the optical power supply 1274 can provide both pulsed light for data modulation and synchronization, as described in U.S. patent application Ser. No. 16/847,705. This allows the high-capacity chip 1262 to be synchronized with the lower-capacity chips 1264a and 1264b.

[0506] Some aspects of the systems 1250, 1260, and 1270 are described in more detail in connection with FIGS. 79 to 84B.

[0507] FIG. 43 shows an exploded view of an example of a front-mounted module 860 of a data processing system that includes a vertically mounted printed circuit board 862, a host application specific integrated circuit 864 mounted on the back-side of the circuit board 862, and a heat sink 866. In some examples, the host application specific integrated circuit 864 is mounted on a substrate (e.g., a ceramic substrate), and the substrate is attached to the circuit board 862. The front module 860 can be, e.g., the front panel of the housing of the data processing system, similar to the configuration shown in FIG. 26, or positioned near the front panel of the housing, similar to the configuration shown in FIG. 27. Three optical module with connectors, e.g., 868a, 868b, 868c, collectively referenced as 868, are shown in the figure. Additional optical module with connectors can be used. The data processing system can be similar to, e.g., the data processing system 680 (FIG. 26) or 700 (FIG. 27). The printed circuit board 862 can be similar to, e.g., the printed circuit board 686 (FIG. 26) or 706 (FIG. 27). The application specific integrated circuit 864 can be similar to, e.g., the application specific integrated circuit 682 (FIG. 26) or 702 (FIG. 27). The heat sink 866 can be similar to, e.g., the heat sink 576 (FIG. 23). The optical module with connector 868 includes an optical module 880 (see FIGS. 44, 45) and a mechanical connector structure 900 (see FIGS. 46, 47). The optical module 880 can be similar to, e.g., the optical modules 648 (FIG. 26) or 704 (FIG. 27).

[0508] The optical module with connector 868 can be inserted into a first grid structure 870, which can function as both (i) a heat spreader/heat sink and (ii) a mechanical holding fixture for the optical module with connectors 868. The first grid structure 870 includes an array of receptors, each receptor can receive an optical module with connector 868. When assembled, the first grid structure 870 is connected to the printed circuit board 862. The first grid structure 870 can be firmly held in place relative to the printed circuit board 862 by sandwiching the printed circuit board 862 in between the first grid structure 870 and a second structure 872 (e.g., a second grid structure) located on the opposite side of the printed circuit board 862 and connected to the first grid structure 870 through the printed circuit board 862, e.g., by use of screws. Thermal vias between the first grid structure 870 and the second structure 872 can conduct heat from the front-side of the printed circuit board 862 to the heat sink 866 on the back-side of the printed circuit board 862. Additional heat sinks can also be mounted directly onto the first grid structure 870 to provide cooling in the front.

[0509] The printed circuit board 862 includes electrical contacts 876 configured to electrically connect to the removable optical module with connectors 868 after the removable optical module with connectors 868 are inserted into the first grid structure 870. The first grid structure 870 can include an opening 874 at the location in which the host application specific integrated circuit 864 is mounted on the other side of the printed circuit board 862 to allow for components such as decoupling capacitors to be mounted on the printed circuit board 862 in immediate lateral vicinity to the host application specific integrated circuit 864.

[0510] FIGS. 44 and 45 show an exploded view and an assembled view, respectively, of the optical module 880, which can be similar to the integrated optical communication device 512 of FIG. 32. The optical module 880 includes an optical connector part 882 (which can be similar to the first optical connector 520 of FIG. 32) that can either directly or through an (e.g., geometrically wider) upper connector part 884 receive light from fibers embedded in a second optical connector part (not shown in FIGS. 44, 45), which can be similar to, e.g., the optical connector part 268 of FIGS. 6 and 7). In the example shown in FIGS. 44, 45, a matrix of fibers, e.g., 2×18 fibers, can be optically coupled to the optical connector part 882. For example, the optical connector part 882 can have a configuration similar to the fiber coupling region 430 of FIG. 15 that is configured to couple 2×18 fibers. The upper connector part 884 can also include alignment structures 886 (e.g., holes, grooves, posts) to receive corresponding mating structures of the second optical connector part.

[0511] The optical connector part 882 is inserted through an opening 888 of a substrate 890 and optically coupled to a photonic integrated circuit 896 mounted on the underside of the substrate 890. The substrate 890 can be similar to the substrate 514 of FIG. 32, and the photonic integrated circuit 896 can be similar to the photonic integrated circuit 524. A first serializers/deserializers chip 892 and a second serializers/deserializers chip 894 are mounted on the substrate 890, in which the chip 892 is positioned on one side of the optical connector part 882, and the chip 894 is positioned on the other side of the optical connector part 882. The first serializers/deserializers chip 892 can include circuitry similar to, e.g., the third serializers/deserializers module 398 and the fourth serializers/deserializers module 400 of FIG. 32. The second serializers/deserializers chip 894 can include circuitry similar to, e.g., the first serializers/deserializers module 394 and the second serializers/deserializers module 396. A second slab 898 (which can be similar to the second slab 518 of FIG. 32) can be provided on the underside of the substrate 890 to provide a removable connection to a package substrate (e.g., 230).

[0512] FIGS. 46 and 47 show an exploded view and an assembled view, respectively, of a mechanical connector structure 900 built around the functional optical module 880 of FIGS. 44, 45. In this example embodiment, the mechanical connector structure 900 includes a lower mechanical part 902 and an upper mechanical part 904 that together receive the optical module 880. Both lower and upper mechanical connector parts 902, 904 can be made of a heat-conducting and rigid material, e.g., a metal.

[0513] In some implementations, the upper mechanical part 904, at its underside, is brought in thermal contact with the first serializers/deserializers chip 892 and the second serializers/deserializers chip 894. The upper mechanical part 904 is also brought in thermal contact with the lower mechanical part 902. The lower mechanical part 902 includes a removable latch mechanism, e.g., two wings 906 that can be elastically bent inwards (the movement of the wings 906 are represented by a double-arrow 908 in FIG. 47), and each wing 906 includes a tongue 910 on an outer side.

[0514] FIG. 48 is a diagram of a portion of the first grid structure 870 and the circuit board 862. Grooves 920 are provided on the walls of the first grid structure 870. As shown in the figure, the printed circuit board 862 has electrical contacts 876 that can be electrically coupled to electrical contacts on the second slab 898 of the optical module 880.

[0515] Referring to FIG. 49, when the lower mechanical part 902 is inserted into the first grid structure 870, the tongues 910 (on the wings 906 of the lower mechanical part 902) can snap into corresponding grooves 920 within the first grid structure 870 to mechanically hold the optical module 880 in place. The position of the tongues 910 on the wings 906 is selected such that when the mechanical connector structure 900 and the optical module 880 are inserted into the first grid structure 870, the electrical connectors at the bottom of the second slab 898 are electrically coupled to the electrical contacts 876 on the printed circuit board 862. For example, the second slab 898 can include spring-loaded contacts that are mated with the contacts 876.

[0516] FIG. 50 shows the front-view of an assembled front module 860. Three optical module with connectors (e.g., 868a, 868b, 868c) are inserted into the first grid structure 870. In some embodiments, the optical modules 880 are arranged in a checkerboard pattern, whereby adjacent optical modules 880 and the corresponding mechanical connector structure 900 are rotated by 90 degrees such as to not allow any two wings to touch. This facilitates the removal of individual modules. In this example, the optical module with connector 868a is rotated 90 degrees relative to the optical module with connectors 868b, 868c.

[0517] FIG. 51A shows a first side view of the mechanical connector structure 900. FIG. 51B shows a cross-sectional view of the mechanical connector structure 900 along a plane 930 shown in FIG. 51A.

[0518] FIG. 52A shows a first side view of the mechanical connector structure 900 mounted within the first grid structure 870. FIG. 52B shows a cross-sectional view of the mechanical connector structure 900 mounted within the first grid structure 870 along a plane 940 shown in FIG. 52A.

[0519] FIG. 53 is a diagram of an assembly 958 that includes a fiber cable 956 that includes a plurality of optical fibers, an optical fiber connector 950, the mechanical connector module 900, and the first grid structure 870. The optical fiber connector 950 can be inserted into the mechanical connector module 900, which can be further inserted into the first grid structure 870. The printed circuit board 862 is attached to the first grid structure 870, in which the electrical contacts 876 face electrical contacts 954 on the bottom side of the second slab 898 of the optical module 880.

[0520] FIG. 53 shows the individual components before they are connected. FIG. 54 is a diagram that shows the components after they are connected. The optical fiber connector 950 includes a lock mechanism 952 that disables the snap-in mechanism of the mechanical connector structure 900 so as to lock in place the mechanical connector structure 900 and the optical module 880. In this example embodiment, the lock mechanism 952 includes studs on the optical fiber connector 950 that insert between the wings 906 and the upper mechanical part 904 of the mechanical connector module 900, hence disabling the wings 906 from elastically bending inwards and consequentially locking the mechanical connector structure 900 and the optical module 880 in place. Further, the mechanical connector structure 900 includes a mechanism to hold the optical fiber connector 950 in place, such as a ball-detent mechanism as shown in the figure. When the optical fiber connector 950 is inserted into the mechanical connector structure 900, spring-loaded balls 962 on the optical fiber connector 950 engage detents 964 in the wings 906 of the mechanical connector structure 900. The springs push the balls 962 against the detents 964 and secure the optical fiber connector 950 in place.

[0521] To remove the optical module 880 from the first grid structure 870, the user can pull the optical fiber connector 950 and cause the balls 962 to disengage from the detents 964. The user can then bend the wings 906 inwards so that the tongues 910 disengage from the grooves 920 on the walls of the first grid structure 870.

[0522] FIGS. 55A and 55B show perspective views of the mechanisms shown in FIGS. 53 and 54 before the optical fiber connector 950 is inserted into the mechanical connector structure 900. As shown in FIG. 55B, the lower side of the optical connector 950 includes alignment structures 960 that mate with the alignment structures 886 (FIG. 44) on the upper connector part 884 of the optical module 880. FIG. 55B also shows the photonic integrated circuit 896 and the second slab 898 that includes electrical contacts (e.g., spring-loaded electrical contacts).

[0523] FIG. 56 is a perspective view showing that the optical module 880 and the mechanical connector structure 900 are inserted into the first grid structure 870, and the optical fiber connector 950 is separated from the mechanical connector structure 900.

[0524] FIG. 57 is a perspective view showing that the optical fiber connector 950 is mated with the mechanical connector structure 900, locking the optical module 880 within the mechanical connector structure 900.

[0525] FIGS. 58A to 58D show an alternate embodiment in which an optical module with connector 970 includes a latch mechanism 972 that acts as a mechanical fastener that joins the optical module 880 to the printed circuit board 862 using the first grid structure 870 as a support. For example, the user can easily attach or remove the optical module with connector 970 by pressing a lever 974 activating the latch mechanism 972. The lever 974 is built in a way that it does not block the optical fibers (not shown in the figure) coming out of the optical module with connector 970. Alternatively, an external tool can be used as a removable lever.

[0526] FIG. 59 is a view of an optical module 1030 that includes an optical engine with a latch mechanism used to realize the compression and attachment of the optical engine to the printed circuit board. The module 1030 is similar to the example shown in FIG. 58B but without the compression interposer. FIGS. 60A and 60B show how the latch mechanism can be used for securing (with enough compression force) and removing the optical engine.

[0527] FIGS. 60A and 60B show an example implementation of the lever 974 and the latch mechanism 972 in the optical module 1030. FIG. 60A shows an example in which the lever 974 is pushed down, causing the latch mechanism 972 to latch on to a support structure 976, which can be part of the first grid structure 870. FIG. 60B shows an example in which the lever 974 is pulled up, causing the latch mechanism 972 to be released from the support structure 976.

[0528] FIG. 61 is a diagram of an example of a fiber cable connection design 980 that includes nested fiber optic cable and co-packaged optical module connections. In this design, a co-packaged optical module 982 is removably coupled to a co-packaged optical port 1000 formed in a support structure, such as the first grid structure 870, and a fiber connector 983 is removably coupled to the co-packaged optical module 982. The fiber connector 983 is coupled to a fiber cable 996 that includes a plurality of optical fibers. The fiber cable connection can be designed to be, e.g., MTP/MPO (Multi-fiber Termination Push-on/Multi-fiber Push On) compatible, or compatible to new standards as they emerge. Multi-fiber push on (MPO) connectors are commonly used to terminate multi-fiber ribbon connections in indoor environments and conforms to IEC-61754-7; EIA/TIA-604-5 (FOCIS 5) standards.

[0529] In some implementations, the co-packaged optical module 982 includes a mechanical connector structure 984 and a smart optical assembly 986. The smart optical assembly 986 includes, e.g., a photonic integrated circuit (e.g., 896 of FIG. 44), and components for guiding light, power splitting, polarization management, optical filtering, and other light beam management before the photonic integrated circuit. The components can include, e.g., optical couplers, waveguides, polarization optics, filters, and/or lenses. The mechanical connector structure 984 includes one or more fiber connector latches 988 and one or more co-packaged optical module latches 990. The mechanical connector structure 984 can be inserted into the co-packaged optical port 1000 (e.g., formed in the first grid structure 870), in which the co-packaged optical module latches 990 engage grooves 992 in the walls of the first grid structure 870, thus securing the co-packaged optical module 982 to the co-packaged optical port 1000, and causing the electrical contacts of the smart optical assembly 986 to be electrically coupled to the electrical contacts 876 on the printed circuit board 862. When the fiber connector 983 is inserted into the mechanical connector structure 984, the fiber connector latches 988 engage grooves 994 in the fiber connector 983, thus securing the fiber connector 983 to the co-packaged optical module 982, and causing the fiber cable 996 to be optically coupled to the smart optical assembly 986, e.g., through optical paths in the fiber connector 983.

[0530] In some examples, the fiber connector 983 includes guide pins 998 that are inserted into holes in the smart optical assembly 986 to improve alignment of optical components (e.g., waveguides and/or lenses) in the fiber connector 983 to optical components (e.g., optical couplers and/or waveguides) in the smart optical assembly 986. In some examples, the guide pins 998 can be chamfered shaped, or elliptical shaped that reduces wear.

[0531] In some implementations, after the fiber connector 983 is installed in the co-packaged optical module 982, the fiber connector 983 prevents the co-packaged optical module latches 990 from bending inwards, thus preventing the co-packaged optical module 982 from being inserted into, or released from, the co-packaged optical port 1000. To couple the fiber cable 996 to the data processing system, the co-packaged optical module 982 is first inserted into the co-packaged optical port 1000 without the fiber connector 983, then the fiber connector 983 is inserted into the mechanical connector structure 984. To remove the fiber cable 996 from the data processing system, the fiber connector 983 can be removed from the mechanical connector structure 984 while the co-packaged optical module 982 is still coupled to the co-packaged optical port 1000.

[0532] In some implementations, the nested connection latches can be designed to allow the co-packaged optical module 982 to be inserted in, or removed from, the co-packaged optical port 1000 when a fiber cable is connected to the co-packaged optical module 982.

[0533] FIGS. 62 and 63 are diagrams showing cross-sectional views of an example of a fiber cable connection design 1010 that includes nested fiber optic cable and co-packaged optical module connections. FIG. 62 shows an example in which a fiber connector 1012 is removably coupled to a co-packaged optical module 1014. FIG. 63 shows an example in which the fiber connector 1012 is separated from the co-packaged optical module 1014.

[0534] FIGS. 64 and 65 are diagrams showing additional cross-sectional views of the fiber cable connection design 1010. The cross-sections are made along planes that vertically cut through the middle of the components shown in FIGS. 62 and 63. FIG. 64 shows an example in which the fiber connector 1012 is removably coupled to the co-packaged optical module 1014. FIG. 65 shows an example in which the fiber connector 1012 is separated from the co-packaged optical module 1014.

[0535] The following describes rack unit thermal architectures for rackmount systems (e.g., 560 of FIG. 22, 600 of FIG. 23, 630 of FIG. 24, 680 of FIG. 26, 720 of FIG. 28, 750 of FIG. 29, 860 of FIG. 43) that include data processing chips (e.g., 572 of FIGS. 22, 23, 640 of FIG. 24, 682 of FIG. 26, 722 of FIG. 28, 758 of FIG. 29, 864 of FIG. 43) that are mounted on vertically oriented circuit boards that are substantially vertical to the bottom surfaces of the system housings or enclosures. In some implementations, the rack unit thermal architectures use air cooling to remove heat generated by the data processing chips. In these systems, the heat-generating data processing chips are positioned near the input/output interfaces, which can include, e.g., one or more of the integrated optical communication device 448, 462, 466, or 472 of FIG. 17, the integrated communication device 574 of FIG. 22 or 612 of FIG. 23, the optical/electrical communication interface 644 of FIG. 24, 684 of FIG. 26, 724 of FIG. 28, or 760 of FIG. 29, or the optical module with connector 868 of FIG. 43, that are positioned at or near the front panel to enable users to conveniently connect/disconnect optical transceivers to/from the rackmount systems. The rack unit thermal architectures described in this specification include mechanisms for increasing airflow across the surfaces of the data processing chips, or heat sinks thermally coupled to the data processing chips, taking into consideration that a substantial portion of the surface area on the front panel of the housing needs to be allocated to the input/output interfaces.

[0536] Referring to FIG. 67, a data server 1140 suitable for installation in a standard server rack can include a housing 1042 that has a front panel 1034, a rear panel 1036, a bottom panel 1038, a top panel, and side panels 1040. For example, the housing 1042 can have a 2 rack unit (RU) form factor, having a width of about 482.6 mm (19 inches) and a height of 2 rack units. One rack unit is about 44.45 mm (approximately 1.75 inches). A printed circuit board 1042 is mounted on the bottom panel 1038, and at least one data processing chip 1044 is electrically coupled to the printed circuit board 1042. A microcontroller unit 1046 is provided to control various modules, such as power supplies 1048 and exhaust fans 1050. In this example, the exhaust fans 1050 are mounted at the rear panel 1036. For example, single mode optical connectors 1052 are provided at the front panel 1034 for connection to external optical cables. Optical interconnect cables 1036 transmit signals between the single mode optical connectors 1052 and the at least one data processing chip 1044. The exhaust fans 1050 mounted at the rear panel 1036 cause the air to flow from the front side to the rear side of the housing 1042. The directions of air flow are represented by arrows 1058. Warm air inside the housing 1042 is vented out of the housing 1042 through the exhaust fans 1050 at the rear panel 1036. In this example, the front panel 1034 does not include any fan in order to maximize the area used for the single mode optical connectors 1052.

[0537] For example, the data server 1300 can be a network switch server, and the at least one data processing chip 1044 can include at least one switch chip configured to process data having a total bandwidth of, e.g., about 51.2 Tbps. The at least one switch chip 1044 can be mounted on a substrate 1054 having dimensions of, e.g., about 100 mm×100 mm, and co-packaged optical modules 1056 can be mounted near the edges of the substrate 1054. The co-packaged optical modules 1056 convert input optical signals received from the optical interconnect cables 1036 to input electrical signals that are provided to the at least one switch chip 1044, and converts output electrical signals from the at least one switch chip 1044 to output optical signals that are provided to the optical interconnect cables 1036. When any of the co-packaged optical modules 1056 fails, the user needs to remove the network switch server 1030 from the server rack and open the housing 1042 in order to repair or replace the faulty co-packaged optical module 1056.

[0538] Referring to FIGS. 68A and 68B, in some implementations, a rackmount server 1060 includes a housing or case 1062 having a front panel 1064 (or face plate), a rear panel 1036, a bottom panel 1038, a top panel, and side panels 1040. For example, the housing 1062 can have a form factor of 1RU, 2RU, 3RU, or 4RU, having a width of about 482.6 mm (19 inches) and a height of 1, 2, 3, or 4 rack units. A first printed circuit board 1066 is mounted on the bottom panel 1038, and a microcontroller unit 1046 is electrically coupled to the first printed circuit board 1066 and configured to control various modules, such as power supplies 1048 and exhaust fans 1050.

[0539] In some implementations, the front panel 1064 includes a second printed circuit board 1068 that is oriented in a vertical direction, e.g., substantially perpendicular to the first circuit board 1066 and the bottom panel 1038. In the following, the second printed circuit board 1068 is referred to as the vertical printed circuit board 1068. The figures shows that the second printed circuit board 1066 forms part of the front panel 1064, but in some examples the second printed circuit board 1066 can also be attached to the front panel 1064, in which the front panel 1064 includes openings to allow input/output connectors to pass through. The second printed circuit board 1066 includes a first side facing the front direction relative to the housing 1062 and a second side facing the rear direction relative to the housing 1062. At least one data processing chip 1070 is electrically coupled to the second side of the vertical printed circuit board 1068, and a heat dissipating device or heat sink 1072 is thermally coupled to the at least one data processing chip 1070. In some examples, the at least one data processing chip 1070 is mounted on a substrate (e.g., a ceramic substrate), and the substrate is attached to the printed circuit board 1068. FIG. 68C is a perspective view of an example of the heat dissipating device or heat sink 1072. For example, the heat dissipating device 1072 can include a vapor chamber thermally coupled to heat sink fins. The exhaust fans 1050 mounted at the rear panel 1036 cause the air to flow from the front side to the rear side of the housing 1042. The directions of air flow are represented by arrows 1078. Warm air inside the housing 1042 is vented out of the housing 1042 through the exhaust fans 1050 at the rear panel 1036.

[0540] Co-packaged optical modules 1074 (also referred to as the optical/electrical communication interfaces) are attached to the first side (i.e., the side facing the front exterior of the housing 1062) of the vertical printed circuit board 1068 for connection to external fiber cables 1076. Each fiber cable 1076 can include an array of optical fibers. By placing the co-packaged optical modules 1074 on the exterior side of the front panel 1064, the user can conveniently service (e.g., repair or replace) the co-packaged optical modules 1074 when needed. Each co-packaged optical module 1074 is configured to convert input optical signals received from the external fiber cable 1076 into input electrical signals that are transmitted to the at least one data processing chip 1070 through signal lines in or on the vertical printed circuit board 1068. The co-packaged optical module 1074 also converts output electrical signals from the at least one data processing chip 1070 into output optical signals that are provided to the external fiber cables 1076. Warm air inside the housing 1062 is vented out of the housing 1062 through the exhaust fans 1050 mounted at the rear panel 1036.

[0541] For example, the at least one data processing chip 1070 can include a network switch, a central processor unit, a graphics processor unit, a tensor processing unit, a neural network processor, an artificial intelligence accelerator, a digital signal processor, a microcontroller, or an application specific integrated circuit (ASIC). For example, each co-packaged optical module 1074 can include a module similar to the integrated optical communication device 448, 462, 466, or 472 of FIG. 17, the integrated optical communication device 210 of FIG. 20, the integrated communication device 612 of FIG. 23, the optical/electrical communication interface 684 of FIG. 26, 724 of FIG. 28, or 760 of FIG. 29, the integrated optical communication device 512 of FIG. 32, or the optical module with connector 868 of FIG. 43. For example, each fiber cable 1076 can include the optical fibers 226 (FIGS. 2, 4), 272 (FIGS. 6, 7), 582 (FIGS. 22, 23), or 734 (FIG. 28), or the optical fiber cable 762 (FIG. 762), 956 (FIG. 53), or 996 (FIG. 61).

[0542] For example, the co-packaged optical module 1074 can include a first optical connector part (e.g., 456 of FIG. 17, 578 of FIG. 22 or 23, 746 of FIG. 28) that is configured to be removably coupled to a second optical connector part (e.g., 458 of FIG. 17, 580 of FIG. 22 or 23, 748 of FIG. 28) that is attached to the external fiber cable 1076. For example, the co-packaged optical module 1074 includes a photonic integrated circuit (e.g., 450, 464, 468, or 474 of FIG. 17, 586 of FIG. 22, 618 of FIG. 23, or 726 of FIG. 28) that is optically coupled to the first optical connector part. The photonic integrated circuit receives input optical signals from the first optical connector part and generates input electrical signals based on the input optical signals. At least a portion of the input electrical signals generated by the photonic integrated circuit are transmitted to the at least one data processing chip 1070 through electrical signal lines in or on the vertical printed circuit board 1068. For example, the photonic integrated circuit can be configured to receive output electrical signals from the at least one data processing chip 1070 and generate output optical signals based on the output electrical signals. The output optical signals are transmitted through the first and second optical connector parts to the external fiber cable 1076.

[0543] In some examples, the fiber cable 1076 can include, e.g., 10 or more cores of optical fibers, and the first optical connector part is configured to couple 10 or more channels of optical signals to the photonic integrated circuit. In some examples, the fiber cable 1076 can include 100 or more cores of optical fibers, and the first optical connector part is configured to couple 100 or more channels of optical signals to the photonic integrated circuit. In some examples, the fiber cable 1076 can include 500 or more cores of optical fibers, and the first optical connector part is configured to couple 500 or more channels of optical signals to the photonic integrated circuit. In some examples, the fiber cable 1076 can include 1000 or more cores of optical fibers, and the first optical connector part is configured to couple 1000 or more channels of optical signals to the photonic integrated circuit.

[0544] In some implementations, the photonic integrated circuit can be configured to generate first serial electrical signals based on the received optical signals, in which each first serial electrical signal is generated based on one of the channels of first optical signals. Each co-packaged optical module 1074 can include a first serializers/deserializers module that includes serializer units and deserializer units, in which the first serializers/deserializers module is configured to generate sets of first parallel electrical signals based on the first serial electrical signals and condition the electrical signals, and each set of first parallel electrical signals is generated based on a corresponding first serial electrical signal. Each co-packaged optical module 1074 can include a second serializers/deserializers module that includes serializer units and deserializer units, in which the second serializers/deserializers module is configured to generate second serial electrical signals based on the sets of first parallel electrical signals, and each second serial electrical signal is generated based on a corresponding set of first parallel electrical signals.

[0545] In some examples, the rackmount server 1060 can include 4 or more co-packaged optical modules 1074 that are configured to be removably coupled to corresponding second optical connector parts that are attached to corresponding fiber cables 1076. For example, the rackmount server 1060 can include 16 or more co-packaged optical modules 1074 that are configured to be removably coupled to corresponding second optical connector parts that are attached to corresponding fiber cables 1076. In some examples, each fiber cable 1076 can include 10 or more cores of optical fibers. In some examples, each fiber cable 1076 can include 100 or more cores of optical fibers. In some examples, each fiber cable 1076 can include 500 or more cores of optical fibers. In some examples, each fiber cable 1076 can include 1000 or more cores of optical fibers. Each optical fiber can transmit one or more channels of optical signals. For example, the at least one data processing chip 1070 can include a network switch that is configured to receive data from an input port associated with a first one of the channels of optical signals, and forward the data to an output port associated with a second one of the channels of optical signals.

[0546] In some implementations, the co-packaged optical modules 1074 is removably coupled to the vertical printed circuit board 1068. For example, the co-packaged optical modules 1074 can be electrically coupled to the vertical printed circuit board 1068 using electrical contacts that include, e.g., spring-loaded elements, compression interposers, or land-grid arrays.

[0547] Referring to FIGS. 69A and 69B, in some implementations, a rackmount server 1080 includes a housing 1082 having a front panel 1084. The rackmount server 1080 is similar to the rackmount server 1060 of FIG. 68A, except that one or more fans are mounted on the front panel 1084, and one or more air louvers installed in the housing 1082 to direct air flow towards the heat dissipating device. For example, the rackmount server 1080 can include a first inlet fan 1086a mounted on the front panel 1084 to the left of the vertical printed circuit board 1068, and a second inlet fan 1086b mounted on the front panel 1084 to the right of the vertical printed circuit board 1068. The terms “right” and “left” refer to relative positions of components shown in the figure. It is understood that, depending on the orientation of a device having a first and second modules, a first module that is positioned to the “left” or “right” of a second module can in fact be to the “right” or “left” (or any other relative position) of the second module. The inlet and exhaust fans operate in a push-pull manner, in which the inlet fans 1086a and 1086b (collectively referenced as 1086) pull cool air into the housing 1082, and the exhaust fans 1050 push warm air out of the housing 1082. The inlet fans 1086 in the front panel or face plate 1064 and the exhaust fans 1050 on the backside of the rack generate a pressure gradient through the housing or case to improve air cooling compared to standard 1RU implementations that include on backside exhaust fans.

[0548] In some implementations, a left air louver 1088a and a right air louver 1088b are installed in the housing 1082 to direct airflow toward the heat dissipating device 1072. The air louvers 1088a, 1088b (collectively referenced as 1088) partitions the space in the housing 1082 and forces air to flow from the inlet fans 1086a and 1086b, pass over surfaces of fins of the heat dissipating device 1072, and towards an opening 1090 between distal ends of the air louvers 1088. The directions of air flow near the inlet fans 1086a and 1086b are represented by arrows 1092a and 1092b. The air louvers 1088 increase the amount of air flows across the surfaces of the heat sink fins and enhance the efficiency of heat removal. The heat sink fins are oriented to extend along planes that are substantially parallel to the bottom surface 1038 of the housing 1082. For example, the air louvers 1088 can have a curved shape, e.g., an S-shape as shown in the figure. The curved shape of the air louvers 1088 can be configured to maximize the efficiency of the heat sink. In some examples, the air louvers 1088 can also have a linear shape.

[0549] For example, the heat sink can be a plate-fin heat sink, a pin-fin heat sink, or a plate-pin-fin heat sink. The pins can have a square or circular cross section. The heat sink configuration (e.g., pin pitch, length of pins or fins) and the louver configuration can be designed to optimize heat sink efficiency.

[0550] For example, the co-packaged optical modules 1074 can be electrically coupled to the vertical printed circuit board 1068 using electrical contacts that include, e.g., spring-loaded elements, compression interposers, or land-grid arrays. For example, when compression interposers are used, the vertical circuit board 1068 can be positioned such that the face of compression interposers of the co-packaged optical module 1074 is coplanar with the face plate 1064 and the inlet fans 1086.

[0551] Referring to FIG. 70, in some implementations, a rackmount server 1090 is similar to the rackmount server 1080 of FIG. 69, which includes inlet fans mounted on the front panel. The inlet fans of the rackmount server 1090 are slightly rotated, as compared to the inlet fans of the rackmount server 1080 to improve efficiency of the heat sink. The rotational axes of the inlet fans, instead of being parallel to the front-to-rear direction relative to the housing 1082, can be rotated slightly inwards. For example, the rotational axis of a left inlet fan 1092a can be rotated slightly clockwise and the rotational axis of a right inlet fan 1092b can be rotated slightly counter-clockwise, to enhance the air flow across the surfaces of the heat sink fins, further improving the efficiency of heat removal.

[0552] In some implementations heat removal efficiency can be improved by positioning the vertical circuit board 1068 and the heat dissipating device 1072 further toward the rear of the housing so that a larger amount of air flows across the surface of the fins of the heat dissipating device 1072.

[0553] Referring to FIGS. 71A to 71B, a rackmount server 1100 includes a housing 1102 having a front panel or face plate 1104, in which the portion of the face plate 1104 where the compression interposers for the co-packaged optical module 1074 are located are inset by a distance d with respect to the original face plate 1104. The face plate 1104 has a recessed portion or an inset portion 1106 that is offset at a distance d (referred to as the “front panel inset distance”) toward the rear of the housing 1102 relative to the other portions (e.g., the portions on which the inlet fans 1086a and 1086b are mounted) of the front panel 1104. The inset portion 1106 is referred to as the “recessed front panel,” “recessed face plate,” “front panel inset,” or “face plate inset.” The vertical printed circuit board 1068 is attached to the inset portion 1106, which includes openings to allow the co-packaged optical modules 1074 to pass through. The inset portion 1106 is configured to have sufficient area to accommodate the co-packaged optical modules 1074.

[0554] By providing the inset portion 1106 in the front panel 1104, the fins of the heat dissipating device 1072 can be more optimally positioned to be closer to the main air flow generated by the inlet fans 1086, while maintaining serviceability of the co-packaged optical modules 1074, e.g., allowing the user to repair or replace damaged co-packaged optical modules 1074 without opening the housing 1102. The heat sink configuration (e.g., pin pitch, length of pins or fins) and the louver configuration can be designed to optimize heat sink efficiency. In addition, the front panel inset distance d can be optimized to improve heat sink efficiency.

[0555] Referring to FIG. 72, in some implementations, a rackmount server 1110 is similar to the rackmount server 1100 of FIG. 71, except that the server 1110 includes a heat dissipating device 1112 that has fins 1114a and 1114b that extend beyond the edge of the vertical printed circuit board 1068 and closer to the inlet fans 1086a, 1086b, as compared to the fins in the example of FIG. 71. The configuration of the fins (e.g., the shapes, sizes, and number of fins) can be selected to maximize the efficiency of heat removal.

[0556] Referring to FIGS. 73A and 73B, in some implementations, a rackmount server 1120 includes a housing 1122 having a front panel 1124, a rear panel 1036, a bottom panel 1038, a top panel, and side panels 1040. The width and height of the housing 1122 can be similar to those of the housing 1062 of FIG. 68A. The server 1120 includes a first printed circuit board 1066 that extends parallel to the bottom panel 1038, and one or more vertical printed circuit boards, e.g., 1126a and 1126b (collectively referenced as 1126), that are mounted perpendicular to the first printed circuit board 1066. The server 1120 includes one or more inlet fans 1086 mounted on the front panel 1124 and one or more exhaust fans 1050 mounted on the rear panel 1036. The air flow in the housing 1122 is generally in the front-to-rear direction. The directions of the air flows are represented by the arrows 1134.

[0557] Each vertical printed circuit board 1126 has a first surface and a second surface. The first surface defines the length and width of the vertical printed circuit board 1126. The distance between the first and second surfaces defines the thickness of the vertical printed circuit board 1126. The vertical printed circuit board 1126a or 1126b is oriented such that the first surface extends along a plane that is substantially parallel to the front-to-rear direction relative to the housing 1122. At least one data processing chip 1128a or 1128b is electrically coupled to the first surface of the vertical printed circuit board 1126a or 1126b, respectively. In some examples, the at least one data processing chip 1128a or 1128b is mounted on a substrate (e.g., a ceramic substrate), and the substrate is attached to the printed circuit board 1126a or 1126b. A heat dissipating device 1130a or 1130b is thermally coupled to the at least one data processing chip 1128a or 1128b, respectively. The heat dissipating device 1130 includes fins that extend along planes that are substantially parallel to the bottom panel 1038 of the housing 1122. The heat sinks 1130a and 1130b are positioned directly behind to the inlet fans 1086a and 1086b, respectively, to maximize air flow across the fins and/or pins of the heat sinks 1130.

[0558] At least one co-packaged optical module 1132a or 1132b is mounted on the second side of the vertical printed circuit board 1126a or 1126b, respectively. The co-packaged optical modules 1132 are optically coupled, through optical interconnection links, to optical interfaces (not shown in the figure) mounted on the front panel 1124. The optical interfaces are optically coupled to external fiber cables. The orientations of the vertical printed circuit boards 1126 and the fins of the heat dissipating devices 1130 are selected to maximize heat removal.

[0559] Referring to FIGS. 74A to 74B, in some implementations, a rackmount server 1150 includes vertical printed circuit boards 1152a and 1152b (collectively referenced as 1152) that have surfaces that extend along planes substantially parallel to the front-to-rear direction relative to the housing or case, similar to the vertical printed circuit boards 1126a and 1126b of FIG. 73. The rackmount server 1150 includes a housing 1154 that has a modified front panel or face plate 1156 that has an inset portion 1158 configured to improve access and field serviceability of co-packaged optical modules 1160a and 1160b (collectively referenced as 1160) that are mounted on the vertical printed circuit boards 1152a and 1152b, respectively. The inset portion 1158 is referred to as the “front panel inset” or “face plate inset.” The inset portion 1158 has a width w that is selected to enable hot-swap, in-field serviceability of the co-packaged optical modules 1160 to avoid the need to take the rackmount server 1150 out of service for maintenance.

[0560] For example, the inset portion 1158 includes a first wall 1162, a second wall 1164, and a third wall 1166. The first wall 1162 is substantially parallel to the second wall 1164, and the third wall 1166 is positioned between the first wall 1162 and the second wall 1164. For example, the first wall 1162 extends along a direction that is substantially parallel to the front-to-rear direction relative to the housing 1122. The vertical printed circuit board 1152a is attached to the first wall 1162 of the inset portion 1158, and the vertical printed circuit board 1152b is attached to the first wall 1162 of the inset portion 1158. The first wall 1162 includes openings to allow the co-packaged optical modules 1160a to pass through, and the second wall 1164 includes openings to allow the co-packaged optical modules 1160b to pass through. For example, an inlet fan 1086c can be mounted on the third wall 1166.

[0561] Each vertical printed circuit board 1152 has a first surface and a second surface. The first surface defines the length and width of the vertical printed circuit board 1152. The distance between the first and second surfaces defines the thickness of the vertical printed circuit board 1152. The vertical printed circuit board 1152a or 1152b is oriented such that the first surface extends along a plane that is substantially parallel to the front-to-rear direction relative to the housing 1154. At least one data processing chip 1170a or 1170b is electrically coupled to the first surface of the vertical printed circuit board 1152a or 1152b, respectively. In some examples, the at least one data processing chip 1170a or 1170b is mounted on a substrate (e.g., a ceramic substrate), and the substrate is attached to the printed circuit board 1152a or 1152b. A heat dissipating device 1168a or 1168b is thermally coupled to the at least one data processing chip 1170a or 1170b, respectively. The heat dissipating device 1168 includes fins that extend along planes that are substantially parallel to the bottom panel 1038 of the housing 1154. The heat sinks 1168a and 1168b are positioned directly behind to the inlet fans 1086a and 1086b, respectively, to maximize air flow across the fins and/or pins of the heat sinks 1168a and 1168b.

[0562] Referring to FIGS. 75A to 75B, in some implementations, a rackmount server 1180 includes a housing 1182 having a front panel 1184 that has an inset portion 1186 (referred to as the “front panel inset” or “face plate inset”). For example, the inset portion 1186 includes a first wall 1188 and a second wall 1190 that are oriented to make it easier for the user to connect or disconnect the fiber cables (e.g., 1076) to the server 1180, or to service the co-packaged optical modules 1074. For example, the first wall 1188 can be at an angle θ₁ relative to a nominal plane 1192 of the front panel 1184, in which 0<θ₁<90°. The second wall 1190 can be at an angle θ₂ relative to the nominal plane 1192 of the front panel, in which 0<θ₂<90°. The angles θ₁ and θ₂ can be the same or different. The nominal plane 1192 of the front panel 1184 is perpendicular to the side panels 1040 and the bottom panel.

[0563] For example, a first vertical printed circuit board 1152a is attached to the first wall 1188, and a second vertical printed circuit board 1152b is attached to the second wall 1190. Comparing the rackmount server 1180 with the rackmount servers 1060 of FIG. 68A, 1080 of FIG. 69A, and 1100 of FIG. 71, the server 1180 has a larger front panel area due to the angled front panel inset and can be connected to more fiber cables.

[0564] Positioning the first and second walls 1188, 1190 at an angle between 0 and 90° relative to the nominal plane of the front panel improves access and field serviceability of the co-packaged optical modules. Comparing the rackmount server 1180 with the rackmount server 1150 of FIG. 74A, the server 1180 allows the user to more easily access the co-packaged optical modules that are positioned farther away from the nominal plane of the front panel. The angles θ₁ and θ₂ are selected to strike a balance between increasing the number of fiber cables that can be connected to the server and providing easy access to all of the co-packaged optical modules of the server. The front panel inset width and angle are configured to enable hot-swap, in-field serviceability to avoid taking the switch and rack out of service for maintenance.

[0565] For examples, intake fans 1086a and 1086b can be mounted on the front panel 1184. Outside air is drawn in by the intake fans 1086a, 1086b, passes through the surfaces of the fins and/or pins of the heatsinks 1168a, 1168b, and flows towards the rear of the housing 1182. Examples of the flow directions for the air entering through the intake fans 1186a and 1186b are represented by arrows 1198a, 1198b, 1198c, and 1198d.

[0566] Referring to FIGS. 75B and 75C, in some implementations, the front panel 1184 includes an upper air vent 1194a and baffles to direct outside air to enter through the upper air vent 1194a, flows downward and rearward such that the air passes over the surfaces of some of the fins and/or pins of the heat sinks 1186 (e.g., including the fins and/or pins closer to the top of the heat sinks 1186) and then flows toward an intake fan 1086c mounted at or near the distal or rear end of the front panel inset portion 1186. The front panel 1184 includes a lower air vent 1194b and baffles to direct outside air to enter through the lower air vent 1194b, flows upward and rearward such that the air passes over the surfaces of some of the fins and/or pins of the heat sinks 1186 (e.g., including the fins and/or pins closer to the bottom of the heat sinks 1186) and then flows toward the intake fan 1086c. Examples of the air flows through the upper and lower air vents 1194a, 1194b to the intake fan 1086c are represented by arrows 1196a, 1196b, 1196c, and 1196d in FIG. 75C.

[0567] For example, fiber cables connected to the co-packaged optical modules 1074 can block air flow for the intake fan 1086c if the intake fan 1086c is configured to receive air through openings directly in front of the intake fan 1086c. By using the upper air vent 1194a, the lower air vent 1194b, and the baffles to direct air flow as described above, the heat dissipating efficiency of the system can be improved (as compared to not having the air vents 1194 and the baffles).

[0568] Referring to FIG. 76, in some implementations, a network switch system 1210 includes a plurality of rackmount switch servers 1212 installed in a server rack 1214. The network switch rack includes a top of the rack switch 1216 that routes data among the switch servers 1212 within the network switch system 1210, and serves as a gateway between the network switch system 1210 and other network switch systems. The rackmount switch servers 1212 in the network switch system 1210 can be configured in a manner similar to any of the rackmount servers described above or below.

[0569] In some implementations, the examples of rackmount servers shown in in FIGS. 68A, 69A, and 70 can be modified by positioning the vertical printed circuit board behind the front panel. The co-packaged optical modules can be optically connected to fiber connector parts mounted on the front panel through short optical connection paths, e.g., fiber jumpers.

[0570] Referring to FIGS. 77A and 77B, in some implementations, a rackmount server 1220 includes a housing 1222 having a front panel 1224, a rear panel 1036, a top panel 1226, a bottom panel 1038, and side panels 1040. The front panel 1224 can be opened to allow the user to access components without removing the rackmount server 1220 from the rack. A vertically mounted printed circuit board 1230 is positioned substantially parallel to the front panel 1224 and recessed from the front panel 1224, i.e., spaced apart at a small distance (e.g., less than 6 inches, or less than 3 inches, or less than 2 inches) to the rear of the front panel 1224. The printed circuit board 1230 includes a first side facing the front direction relative to the housing 1222 and a second side facing the rear direction relative to the housing 1222. At least one data processing chip 1070 is electrically coupled to the second side of the vertical printed circuit board 1226, and a heat dissipating device or heat sink 1072 is thermally coupled to the at least one data processing chip 1070. In some examples, the at least one data processing chip 1070 is mounted on a substrate (e.g., a ceramic substrate), and the substrate is attached to the printed circuit board 1226.

[0571] Co-packaged optical modules 1074 (also referred to as the optical/electrical communication interfaces) are attached to the first side (i.e., the side facing the front exterior of the housing 1222) of the vertical printed circuit board 1230. In some examples, the co-packaged optical modules 1074 are mounted on a substrate that is attached to the vertical printed circuit board 1230, in which electrical contacts on the substrate are electrically coupled to corresponding electrical contacts on the vertical printed circuit board 1230. In some examples, the at least one data processing chip 1070 is mounted on the rear side of the substrate, and the co-packaged optical modules 1074 are removably attached to the front side of the substrate, in which the substrate provides high speed connections between the at least one data processing chip 1070 and the co-packaged optical modules 1074. For example, the substrate can be attached to a front side of the printed circuit board 1068, in which the printed circuit board 1068 includes one or more openings that allow the at least one data processing chip 1070 to be mounted on the rear side of the substrate. The printed circuit board 1068 can provide from a motherboard electrical power to the substrate (and hence to the at least one data processing chip 1070 and the co-packaged optical modules 1074, and allow the at least one data processing chip 1070 and the co-packaged optical modules 1074 to connect to the motherboard using low-speed electrical links. An array of co-packaged optical modules 1074 can be mounted on the vertical printed circuit board 1230 (or the substrate), similar to the examples shown in FIGS. 69B and 71B. The electrical connections between the co-packaged optical modules 1074 and the vertical printed circuit board 1070 (or the substrate) can be removable, e.g., by using land-grid arrays and/or compression interposers. The co-packaged optical modules 1074 are optically connected to first fiber connector parts 1232 mounted on the front panel 1224 through short fiber jumpers 1234a, 1234b (collectively referenced as 1234). When the front panel 1224 is closed, the user can plug a second fiber connector part 1236 into the first fiber connector part 1232 on the front panel 1224, in which the second fiber connector part 1236 is connected to an optical fiber cable 1238 that includes an array of optical fibers.

[0572] In some implementations, the rackmount server 1220 is pre-populated with co-packaged optical modules 1074, and the user does not need to access the co-packaged optical modules 1074 unless the modules need maintenance. During normal operation of the rackmount server 1220, the user mostly accesses the first fiber connector parts 1232 on the front panel 1224 to connect to fiber cables 1238.

[0573] One or more intake fans, e.g., 1086a, 1086b, can be mounted on the front panel 1224, similar to the examples shown in FIGS. 69A and 70. The positions and configurations of the intake fans 1086, the heat sink 1072, and the air louvers 1088a, 1088b are selected to maximize the heat transfer efficiency of the heat sink 1072.

[0574] The rackmount server 1220 can have a number of advantages. By placing the vertical printed circuit board 1230 at a recessed position inside the housing 1222, the vertical printed circuit board 1230 is better protected by the housing 1222, e.g., preventing users from accidentally bumping into the circuit board 1230. By orienting the vertical printed circuit board 1230 substantially parallel to the front panel 1224 and mounting the co-packaged optical modules 1074 on the side of the circuit board 1230 facing the front direction, the co-packaged optical modules 1074 can be accessible to users for maintenance without the need to remove the rackmount server 1220 from the rack.

[0575] In some implementations, the front panel 1224 is coupled to the bottom panel 1038 using a hinge 1228 and configured such that the front panel 1224 can be securely closed during normal operation of the rackmount server 1220 and easily opened for maintenance. For example, if a co-packaged optical module 1074 fails, a technician can open and rotate the front panel 1224 down to a horizontal position to gain access to the co-packaged optical module 1074 to repair or replace it. For example, the movements of the front panel 1224 is represented by the bi-directional arrow 1250. In some implementations, different fiber jumpers 1234 can have different lengths, depending on the distance between the parts that are connected by the fiber jumpers 1234. For example, the distance between the co-packaged optical module 1074 and the first fiber connector part 1232 connected by the fiber jumper 1234a is less than the distance between the co-packaged optical module 1074 and the first fiber connector part 1232 connected by the fiber jumper 1234b, so the fiber jumper 1234a can be shorter than the fiber jumper 1234b. This way, by using fiber jumpers with appropriate lengths, it is possible to reduce the clutter caused by the fiber jumpers 1234 inside the housing 1222 when the front panel 1224 is closed and in its vertical position.

[0576] In some implementations, the front panel 1224 can be configured to be opened and lifted upwards using lift-up hinges. This can be useful when the rackmount server is positioned near the top of the rack. In some examples, the front panel 1224 can be coupled to the side panel 1040 by using a hinge so that the front panel 1224 can be opened and rotated sideways. In some examples, the front panel can include a left front subpanel and a right front subpanel, in which the left front subpanel is coupled to the left side panel 1040 by using a first hinge, and the right front subpanel is coupled to the right panel 1040 by using a second hinge. The left front subpanel can be opened and rotated towards the left side, and the right front subpanel can be opened and rotated towards the right side. These various configurations for the front panel enable protection of the vertical printed circuit board 1230 and convenient access to the co-packaged optical modules 1074.

[0577] In some examples, the front panel can have an inset portion, similar to the example shown in FIG. 71A, in which the vertical printed circuit board is in a recessed position relative to the inset portion of the front panel, i.e., at a small distance to the rear of the inset portion of the front panel. The front panel inset distance, the distance between the vertical printed circuit board and the front panel inset portion, and the air louver configuration can be selected to maximize the heat sink efficiency.

[0578] Referring to FIG. 78, in some implementations, a rackmount server 1240 can be similar to the rackmount server 1150 of FIG. 74A, except that the vertical printed circuit boards are at recessed positions relative to the walls of the inset portion of the front panel. For example, a vertical printed circuit board 1152a is in a recessed position relative to a first wall 1242a of an inset portion 1244, i.e., the vertical printed circuit board 1152a is spaced apart a small distance to the left from the first wall 1242a. A vertical printed circuit board 1152b is in a recessed position relative to a second wall 1242b of the inset portion 1244, i.e., the vertical printed circuit board 1152b is spaced apart a small distance to the right from the second wall 1242b.

[0579] For example, the first wall 1242a can be coupled to the bottom or top panel through hinges so that the first wall 1242a can be closed during normal operation of the rackmount server 1240 and opened for maintenance of the server 1240. The distance w2 between the first wall 1242a and the second wall 1242b is selected to be sufficiently large to enable the first wall 1242a and the second wall 1242b to be opened properly. This design has advantages similar to those of the rackmount server 1220 in FIGS. 77A, 77B.

[0580] In some implementations, a rackmount server can be similar to the rackmount server 1180 shown in FIGS. 75A to 75C, except that the vertical printed circuit boards are at recessed positions relative to the walls of the inset portion of the front panel. For example, a first vertical printed circuit board is in a recessed position relative to the first wall 1188 of the inset portion 1186, and a second vertical printed circuit board is in a recessed position relative to the second wall 1190 of the inset portion 1186. For example, the first wall 1188 can be coupled to the bottom or top panel through hinges so that the first wall 1188 can be closed during normal operation of the rackmount server and opened for maintenance of the server. The angles θ₁ and θ₂ are selected to enable the first wall 1188 and the second wall 1190 to be opened properly. This design has advantages similar to those of the rackmount server 1220 in FIGS. 77A, 77B.

[0581] A feature of the thermal architecture for the rackmount units (e.g., the rackmount servers 1060 of FIG. 68A, 1090 of FIGS. 69A, 70, 1100 of FIGS. 71A, 72, 1120 of FIG. 73A, 1150 of FIG. 74A, 1180 of FIG. 75A, 1220 of FIG. 77B, and 1240 of FIG. 78) described above is the use of co-packaged optical modules or optical/electrical communication interfaces that have higher bandwidth per module or interface, as compared to conventional designs. For example, each co-packaged optical module or optical/electrical communication interface can be coupled to a fiber cable that carries a large number of densely packed optical fiber cores. FIG. 9 shows an example of the integrated optical communication device 282 in which the optical signals provided to the photonic integrated circuit can have a total bandwidth of about 12.8 Tbps. By using co-packaged optical modules or optical/electrical communication interfaces that have higher bandwidth per module or interface, the number of co-packaged optical modules or optical/electrical communication interfaces required for a given total bandwidth for the rackmount unit is reduced, so the amount of area on the front panel of the housing reserved for connecting to optical fibers can be reduced. Therefore, it is possible to add one or more inlet fans on the front panel to improve thermal management while still maintaining or even increasing the total bandwidth of the rackmount unit, as compared to conventional designs.

[0582] In some implementations, for the examples shown in FIGS. 72, 74A, 75A, and 78, and the variations in which the vertical printed circuit boards are at recessed positions relative to the front panel, the shape of each of the top and bottom panels of the housing can have an inset portion at the front that corresponds to the inset portion of the front panel. This makes it more convenient to access the co-packaged optical modules or the optical connector parts mounted on the front panel without being hindered by the top and bottom panels. In some implementations, the server rack (e.g., 1214 of FIG. 76) is designed such that front support structures of the server rack also have inset portions that correspond to the insert portions of the front panels of the rackmount servers installed in the server rack. For example, a custom server rack can be designed to install rackmount servers that all have the inset portions similar to the inset portion 1158 of FIG. 74A. For example, a custom server rack can be designed to install rackmount servers that all have the inset portions similar to the inset portion 1186 of FIG. 75A. In such examples, the inset portions extend vertically from the bottom-most server to the top-most server without any obstruction, making it easier for the user to access the co-packaged optical modules or optical connector parts.

[0583] In some implementations, for the examples shown in FIGS. 72, 74A, 75A, and 78, and the variations in which the vertical printed circuit boards are at recessed positions relative to the front panel, the shape of the top and bottom panels of the housing can be similar to standard rackmount units, e.g., the top and bottom panels can have a generally rectangular shape.

[0584] In the examples shown in FIGS. 68A, 68B, 69A to 75C, and 77A to 78, a grid structure similar to the grid structure 870 shown in FIG. 43 can be attached to the vertical printed circuit board. The grid structure can function as both (i) a heat spreader/heat sink and (ii) a mechanical holding fixture for the co-packaged optical modules (e.g., 1074) or optical/electrical communication interfaces.

[0585] FIGS. 96 to 97B are diagrams of an example of a rackmount server 1820 that includes a vertically oriented circuit board 1822 positioned at a front portion of the rackmount server 1820. FIG. 96 shows a top view of the rackmount server 1820, FIG. 97A shows a perspective view of the rackmount server 1820, and FIG. 97B shows a perspective view of the rackmount server 1820 with the top panel removed. The rackmount server 1820 has an active airflow management system that is configured to remove heat from a data processor during operation of the rackmount server 1820.

[0586] Referring to FIGS. 96, 97A, and 97B, in some implementations, the rackmount server 1820 includes a housing 1824 that has a front panel 1826, a left side panel 1828, a right side panel 1840, a bottom panel 1841, a top panel 1843, and a rear panel 1842. The front panel 1826 can be similar to the front panels in the examples shown in FIGS. 68A, 68B, 69A to 72, 77A, and 77B. For example, the vertically oriented circuit board 1822 can be part of the front panel 1826, or attached to the front panel 1826, or positioned in a vicinity of the front panel 1826, in which a distance between the circuit board 1822 and the front panel 1826 is not more than, e.g., 6 inches. A data processor 1844 (which can be, e.g., a network switch, a central processor unit, a graphics processor unit, a tensor processing unit, a neural network processor, an artificial intelligence accelerator, a digital signal processor, a microcontroller, or an application specific integrated circuit) (see FIG. 99) is mounted on the circuit board 1822.

[0587] A heat dissipating module 1846, e.g., a heat sink, is thermally coupled to the data processor 1844 and configured to dissipate heat generated by the data processor 1828 during operation. The heat dissipating module 1846 can be similar to the heat dissipating device 1072 of FIGS. 68A, 68C, 69A, 70, and 71A. In some examples, the heat dissipating module 1846 includes heat sink fins or pins having heat dissipating surfaces configured to optimize heat dissipation. In some examples, the heating dissipating module 1846 includes a vapor chamber thermally coupled to heat sink fins or pins. The rackmount server 1820 can include other components, such as power supply units, rear outlet fans, one or more additional horizontally oriented circuit boards, one or more additional data processors mounted on the horizontally oriented circuit boards, and one or more additional air louvers, that have been previously described in other embodiments of rackmount servers and are not repeated here.

[0588] In some implementations, the active airflow management system includes an inlet fan 1848 that is positioned at a left side of the heat dissipating module 1846 and oriented to blow incoming air to the right toward the heat dissipating module 1846. A front opening 1850 provides incoming air for the inlet fan 1848. The front opening 1850 can be positioned to the left of the inlet fan 1848. In the example of FIG. 96, the circuit board 1822 is substantially parallel to the front panel 1826, and the rotational axis of the inlet fan 1848 is substantially parallel to the plane of the circuit board 1822. The inlet fan 1848 can also be oriented slightly differently. For example, the rotational axis of the inlet fan 1848 can be at an angle θ relative to the plane of the front panel 1826, the angle θ being measured along a plane parallel to the bottom panel 1841, in which θ≤45°, or in some examples θ≤25°, or in some examples θ≤5°, or in some examples θ=0°.

[0589] In some implementations, a baffle or an air louver 1852 (or internal panel or internal wall) is provided to guide the air entering the opening 1850 towards the inlet fan 1848. An arrow 1854 shows the general direction of airflow from the opening 1850 to the inlet fan 1848. In some examples, the air louver 1852 extends from the left side panel 1828 of the housing 1840 to a rear edge of the inlet fan 1848. The air louver 1852 can be straight or curved. In some examples, the air louver 1852 can be configured to guide the inlet air blown from the inlet fan 1848 towards the heat dissipating module 1846. For example, the air louver 1852 can extend from the left side panel 1828 to the left edge of the heat dissipating module 1846. For example, the air louver 1852 can extend from the left side panel 1828 to a position at or near the rear of the heat dissipating module 1846, in which the position can be anywhere from the left rear portion of the heat dissipating module 1846 to the right rear portion of the heat dissipating module 1846. The air louver 1852 can extend from the bottom panel 1841 to the top panel 1843 in the vertical direction. An arrow 1856 shows the general direction of air flow through and out of the heating dissipating module 1846.

[0590] For example, the air louver 1852, a front portion of the left side panel 1828, the front panel 1826, the circuit board 1822, a front portion of the bottom panel 1841, and a front portion of the top panel 1843 can form an air duct that guides the incoming cool air to flow across the heat dissipating surface of the heat dissipating module 1846. Depending on the design, the air duct can extend to the left edge of the heat dissipating module 1846, to a middle portion of the heat dissipating module 1846, or extend approximately the entire length (from left to right) of the heat dissipating module 1846.

[0591] The inlet fan 1848 and the air louver 1852 are designed to improve airflow across the heat dissipating surface of the heat dissipating module 1846 to optimize or maximize heat dissipation from the data processor 1844 through the heat dissipating module 1846 to the ambient air. Different rackmount servers can have vertically mounted circuit boards with different lengths, can have data processors with different heat dissipation requirements, and can have heat dissipating modules with different designs. For example, the heat sink fins and/or pins can have different configurations. The inlet fan 1848 and the air louver 1852 can also have any of various configurations in order to optimize or maximize the heat dissipation from the data processor 1844. In the example of FIG. 96, the inlet fan 1848 directs air to flow generally in a direction (in this example, from left to right) that is parallel to the front panel across the heat dissipating surface of the heat dissipating module 1846. In some implementations, the front opening can be positioned to the right side of the front panel, and the inlet fan can be positioned to the right side of the heat dissipating module and direct air to flow from right to left across the heat dissipating surface of the heat dissipating module. The air louver can be modified accordingly to optimize airflow and heat dissipation from the data processor.

[0592] FIG. 98 is a diagram showing the front portion of the rackmount server 1820. The baffle or air louver 1852, a portion of the bottom panel 1841, a portion of the top panel 1843, and a portion of the left side panel 1828 form a duct that directs external air toward the inlet fan 1848. A safety mechanism (not shown in the figure), such as a protective mesh, that allows air to substantially freely pass through while blocking larger objects, such as users' fingers, can be placed across the opening 1850.

[0593] In some examples, orienting the inlet fan to face towards the side direction instead of the front direction (as in the examples shown in FIGS. 69A and 71A) can improve the safety and comfort of users operating the rackmount server 1820. In some examples, orienting the inlet fan towards the side direction instead of the front direction can avoid the presence of a region in the heat dissipating module having little to no air flow. In the example of FIG. 71A, the left and right inlet fans blow air toward the left and right side regions, respectively, of the heat dissipating device 1072. The incoming air is drawn toward the rear of the heat dissipating module due to the air pressure gradient generated by the front and rear inlet fans. In some cases, the incoming air entering the left side of the heat dissipating device 1072 is drawn toward the rear of the heat dissipating device 1072 before reaching the middle part of the heat dissipating device 1072. Similarly, the incoming air entering the right side of the heat dissipating device 1072 is drawn toward the rear of the heat dissipating device 1072 before reaching the middle part of the heat dissipating device 1072. As a result, near the middle or middle-front region of the heat dissipating device 1072 there may be a region having little to no air flow, reducing the efficiency of heat dissipation. The design shown in FIGS. 96 to 98 avoids or reduces this problem.

[0594] The front panel 1826 includes openings or interface ports 1860 that allow the rackmount server 1820 to be coupled to optical fiber cables and/or electrical cables. In some implementations, co-packaged optical modules 1870 can be inserted into the interface ports 1860, in which the co-packaged optical modules 1870 function as optical/electrical communication interfaces for the data processor 1844. The co-packaged optical modules have been described earlier in this document.

[0595] FIG. 99 includes an upper diagram 1880 that shows a perspective front view of an example of the front panel 1826, and a lower diagram 1882 that shows a perspective rear view of the front panel 1826. The lower diagram 1882 shows the data processor 1844 mounted to the back side of the vertically oriented circuit board 1822. The front panel 1826 includes openings or interface ports 1860 that allow insertion of communication interface modules, such as co-packaged optical modules, that provide interfaces between the data processor 1844 and external optical or electrical cables. The optical and electrical signal paths between the data processor 1844 and the co-packaged optical modules have been previously described in this document.

[0596] FIG. 100 is a diagram of a top view of an example of a rackmount server 1890 that includes a vertically oriented circuit board 1822 positioned at a front portion of the rackmount server 1890. A data processor 1844 is mounted on the circuit board 1822, and a heat dissipating module 1846 is thermally coupled to the data processor 1844. The rackmount server 1890 has an active airflow management system that is configured to remove heat from the data processor 1844 during operation. The rackmount server 1890 includes components that are similar to those of the rackmount server 1820 (FIG. 96) and are not otherwise described here.

[0597] In some implementations, the active airflow management system includes an inlet fan 1894 that is positioned at a left side of the heat dissipating module 1846 and oriented to blow inlet air to the right toward the heat dissipating module 1846. A front opening 1850 allows incoming air to pass to the inlet fan 1894. The front opening 1850 can be positioned to the left of the inlet fan 1894. For example, the inlet fan 1894 can have a rotational axis that is at an angle θ relative to the front panel 1826, in which θ≤45°. In some examples, θ≤25°. In some examples, θ<5°. In some examples, the circuit board 1822 is substantially parallel to the front panel 1826, and the rotational axis of the inlet fan 1894 is substantially parallel to the circuit board 1822. An inlet fan 1894,

[0598] In some implementations, a first baffle or air louver 1892 is provided to guide air from the opening 1850 towards the inlet fan 1894, and from the inlet fan 1894 towards the heat dissipating module 1846. A second baffle or air louver 1908 is provided to guide air from the right portion of the heat dissipating module 1846 toward the rear of the rackmount server 1890. The first and second air louvers 1892, 1894 can extend from the bottom panel to the top panel in the vertical direction.

[0599] An arrow 1902 shows a general direction of airflow from the opening 1850 to the inlet fan 1894. An arrow 1904 shows a general direction of airflow from the inlet fan 1894 to, and through, a center portion the heat dissipating module 1846. An arrow 1906 shows a general direction of airflow through, and exiting, the right portion of the heat dissipating module 1846. The first air louver 1892, a front portion of the left panel, a front portion of the top panel, a front portion of the bottom panel, the front panel 1826, the circuit board 1822, and the second air louver 1908 in combination form a duct that channels the air to flow through the entire heat dissipating module 1846, or a substantial portion of the heat dissipating module 1846, thereby increasing the efficiency of heat dissipation from the data processor 1844.

[0600] In this example, the first air louver 1892 includes a left curved section 1896, a middle straight section 1898, and a right curved section 1900. The left curved section 1896 extends from the left side panel to the inlet fan 1894. The left curved section 1896 directs incoming air to turn from flowing in the rear direction to flowing in the left-to-right direction. The middle straight section 1898 is positioned to the rear of the heat dissipating module 1846 and extends from the inlet fan 1894 to beyond the center portion of the heat dissipating module 1846. The middle straight section 1898 directs the air to flow generally in a left-to-right direction through a substantial portion (e.g., more than half) of the heat dissipating module 1846. The right curved section 1900 and the second air louver 1908 in combination guide the air to turn from flowing in the left-to-right direction to flowing in a rear direction. The designs of the first and second air louvers 1892, 1908 are selected to optimize the heat dissipation efficiency. The heat dissipating module 1846 can have a design that is different from what is shown in the figure, and the first and second air louvers 1892, 1908 can also be modified accordingly.

[0601] In the example of FIG. 100, the inlet fan 1894 directs air to flow generally in a direction (in this example, from left to right) that is parallel to the front panel 1826 across the heat dissipating surface of the heat dissipating module 1846. In some implementations, the front opening can be positioned to the left side of the front panel, and the inlet fan can be positioned to the right side of the heat dissipating module and direct air to flow from right to left across the heat dissipating surface of the heat dissipating module. The first and second air louvers can be modified accordingly to optimize airflow and heat dissipation from the data processor.

[0602] FIGS. 35A to 37 show examples of optical communications systems 1250, 1260, 1270 in which in each system an optical power supply or photon supply provides optical power supply light to photonic integrated circuits hosted in multiple communication devices (e.g., optical transponders), and the optical power supply is external to the communication devices. The optical power supply can have its own housing, electrical power supply, and control circuitry, independent of the housings, electrical power supplies, and control circuitry of the communication devices. This allows the optical power supply to be serviced, repaired, or replaced independent of the communication devices. Redundant optical power supplies can be provided so that a defective external optical power supply can be repaired or replaced without taking the communication devices off-line. The external optical power supply can be placed at a convenient centralized location with a dedicated temperature environment (as opposed to being crammed inside the communication devices, which may have a high temperature). The external optical power supply can be built more efficiently than individual power supply units, as certain common parts such as monitoring circuitry and thermal control units can be amortized over many more communication devices. The following describes implementations of the fiber cabling for remote optical power supplies.

[0603] FIG. 79 is a system functional block diagram of an example of an optical communication system 1280 that includes a first communication transponder 1282 and a second communication transponder 1284. Each of the first and second communication transponders 1282, 1284 can include one or more co-packaged optical modules described above. Each communication transponder can include, e.g., one or more data processors, such as network switches, central processing units, graphics processor units, tensor processing units, digital signal processors, and/or other application specific integrated circuits (ASICs). In this example, the first communication transponder 1282 sends optical signals to, and receives optical signals from, the second communication transponder 1284 through a first optical communication link 1290. The one or more data processors in each communication transponder 1282, 1284 process the data received from the first optical communication link 1290 and outputs processed data to the first optical communication link 1290. The optical communication system 1280 can be expanded to include additional communication transponders. The optical communication system 1280 can also be expanded to include additional communication between two or more external photon supplies, which can coordinate aspects of the supplied light, such as the respectively emitted wavelengths or the relative timing of the respectively emitted optical pulses.

[0604] A first external photon supply 1286 provides optical power supply light to the first communication transponder 1282 through a first optical power supply link 1292, and a second external photon supply 1288 provides optical power supply light to the second communication transponder 1284 through a second optical power supply link 1294. In one example embodiment, the first external photon supply 1286 and the second external photon supply 1288 provide continuous wave laser light at the same optical wavelength. In another example embodiment, the first external photon supply 1286 and the second external photon supply 1288 provide continuous wave laser light at different optical wavelengths. In yet another example embodiment, the first external photon supply 1286 provides a first sequence of optical frame templates to the first communication transponder 1282, and the second external photon supply 1288 provides a second sequence of optical frame templates to the second communication transponder 1284. For example, as described in U.S. patent Ser. No. 16/847,705, each of the optical frame templates can include a respective frame header and a respective frame body, and the frame body includes a respective optical pulse train. The first communication transponder 1282 receives the first sequence of optical frame templates from the first external photon supply 1286, loads data into the respective frame bodies to convert the first sequence of optical frame templates into a first sequence of loaded optical frames that are transmitted through the first optical communication link 1290 to the second communication transponder 1284. Similarly, the second communication transponder 1284 receives the second sequence of optical frame templates from the second external photon supply 1288, loads data into the respective frame bodies to convert the second sequence of optical frame templates into a second sequence of loaded optical frames that are transmitted through the first optical communication link 1290 to the first communication transponder 1282.

[0605] FIG. 80A is a diagram of an example of an optical communication system 1300 that includes a first switch box 1302 and a second switch box 1304. Each of the switch boxes 1302, 1304 can include one or more data processors, such as network switches. The first and second switch boxes 1302, 1304 can be separated by a distance greater than, e.g., 1 foot, 3 feet, 10 feet, 100 feet, or 1000 feet. The figure shows a diagram of a front panel 1306 of the first switch box 1302 and a front panel 1308 of the second switch box 1304. In this example, the first switch box 1302 includes a vertical ASIC mount grid structure 1310, similar to the grid structure 870 of FIG. 43. A co-packaged optical module 1312 is attached to a receptor of the grid structure 1310. The second switch box 1304 includes a vertical ASIC mount grid structure 1314, similar to the grid structure 870 of FIG. 43. A co-packaged optical module 1316 is attached to a receptor of the grid structure 1314. The first co-packaged optical module 1312 communicates with the second co-packaged optical module 1316 through an optical fiber bundle 1318 that includes multiple optical fibers. Optional fiber connectors 1320 can be used along the optical fiber bundle 1318, in which shorter sections of optical fiber bundles are connected by the fiber connectors 1320.

[0606] In some implementations, each co-packaged optical module (e.g., 1312, 1316) includes a photonic integrated circuit configured to convert input optical signals to input electrical signals that are provided to a data processor, and convert output electrical signals from the data processor to output optical signals. The co-packaged optical module can include an electronic integrated circuit configured to process the input electrical signals from the photonic integrated circuit before the input electrical signals are transmitted to the data processor, and to process the output electrical signals from the data processor before the output electrical signals are transmitted to the photonic integrated circuit. In some implementations, the electronic integrated circuit can include a plurality of serializers/deserializers configured to process the input electrical signals from the photonic integrated circuit, and to process the output electrical signals transmitted to the photonic integrated circuit. The electronic integrated circuit can include a first serializers/deserializers module having multiple serializer units and deserializer units, in which the first serializers/deserializers module is configured to generate a plurality of sets of first parallel electrical signals based on a plurality of first serial electrical signals provided by the photonic integrated circuit, and condition the electrical signals, in which each set of first parallel electrical signals is generated based on a corresponding first serial electrical signal. The electronic integrated circuit can include a second serializers/deserializers module having multiple serializer units and deserializer units, in which the second serializers/deserializers module is configured to generate a plurality of second serial electrical signals based on the plurality of sets of first parallel electrical signals, and each second serial electrical signal is generated based on a corresponding set of first parallel electrical signals. The plurality of second serial electrical signals can be transmitted toward the data processor.

[0607] The first switch box 1302 includes an external optical power supply 1322 (i.e., external to the co-packaged optical module) that provides optical power supply light through an optical connector array 1324. In this example, the optical power supply 1322 is located internal of the housing of the switch box 1302. Optical fibers 1326 are optically coupled to an optical connector 1328 (of the optical connector array 1324) and the co-packaged optical module 1312. The optical power supply 1322 sends optical power supply light through the optical connector 1328 and the optical fibers 1326 to the co-packaged optical module 1312. For example, the co-packaged optical module 1312 includes a photonic integrated circuit that modulates the power supply light based on data provided by a data processor to generate a modulated optical signal, and transmits the modulated optical signal to the co-packaged optical module 1316 through one of the optical fibers in the fiber bundle 1318.

[0608] In some examples, the optical power supply 1322 is configured to provide optical power supply light to the co-packaged optical module 1312 through multiple links that have built-in redundancy in case of malfunction in some of the optical power supply modules. For example, the co-packaged optical module 1312 can be designed to receive N channels of optical power supply light (e.g., N1 continuous wave light signals at the same or at different optical wavelengths, or N1 sequences of optical frame templates), N1 being a positive integer, from the optical power supply 1322. The optical power supply 1322 provides N1+M1 channels of optical power supply light to the co-packaged optical module 1312, in which M1 channels of optical power supply light are used for backup in case of failure of one or more of the N1 channels of optical power supply light, M1 being a positive integer.

[0609] The second switch box 1304 receives optical power supply light from a co-located optical power supply 1330, which is, e.g., external to the second switch box 1304 and located near the second switch box 1304, e.g., in the same rack as the second switch box 1304 in a data center. The optical power supply 1330 includes an array of optical connectors 1332. Optical fibers 1334 are optically coupled to an optical connector 1336 (of the optical connectors 1332) and the co-packaged optical module 1316. The optical power supply 1330 sends optical power supply light through the optical connector 1336 and the optical fibers 1334 to the co-packaged optical module 1316. For example, the co-packaged optical module 1316 includes a photonic integrated circuit that modulates the power supply light based on data provided by a data processor to generate a modulated optical signal, and transmits the modulated optical signal to the co-packaged optical module 1312 through one of the optical fibers in the fiber bundle 1318.

[0610] In some examples, the optical power supply 1330 is configured to provide optical power supply light to the co-packaged optical module 1316 through multiple links that have built-in redundancy in case of malfunction in some of the optical power supply modules. For example, the co-packaged optical module 1316 can be designed to receive N2 channels of optical power supply light (e.g., N2 continuous wave light signals at the same or at different optical wavelengths, or N2 sequences of optical frame templates), N2 being a positive integer, from the optical power supply 1322. The optical power supply 1322 provides N2+M2 channels of optical power supply light to the co-packaged optical module 1312, in which M2 channels of optical power supply light are used for backup in case of failure of one or more of the N2 channels of optical power supply light, M2 being a positive integer.

[0611] FIG. 80B is a diagram of an example of an optical cable assembly 1340 that can be used to enable the first co-packaged optical module 1312 to receive optical power supply light from the first optical power supply 1322, enable the second co-packaged optical module 1316 to receive optical power supply light from the second optical power supply 1330, and enable the first co-packaged optical module 1312 to communicate with the second co-packaged optical module 1316. FIG. 80C is an enlarged diagram of the optical cable assembly 1340 without some of the reference numbers to enhance clarity of illustration.

[0612] The optical cable assembly 1340 includes a first optical fiber connector 1342, a second optical fiber connector 1344, a third optical fiber connector 1346, and a fourth optical fiber connector 1348. The first optical fiber connector 1342 is designed and configured to be optically coupled to the first co-packaged optical module 1312. For example, the first optical fiber connector 1342 can be configured to mate with a connector part of the first co-packaged optical module 1312, or a connector part that is optically coupled to the first co-packaged optical module 1312. The first, second, third, and fourth optical fiber connectors 1342, 1344, 1346, 1348 can comply with an industry standard that defines the specifications for optical fiber interconnection cables that transmit data and control signals, and optical power supply light.

[0613] The first optical fiber connector 1342 includes optical power supply (PS) fiber ports, transmitter (TX) fiber ports, and receiver (RX) fiber ports. The optical power supply fiber ports provide optical power supply light to the co-packaged optical module 1312. The transmitter fiber ports allow the co-packaged optical module 1312 to transmit output optical signals (e.g., data and/or control signals), and the receiver fiber ports allow the co-packaged optical module 1312 to receive input optical signals (e.g., data and/or control signals). Examples of the arrangement of the optical power supply fiber ports, the transmitter ports, and the receiver ports in the first optical fiber connector 1342 are shown in FIGS. 80D, 89, and 90.

[0614] FIG. 80D shows an enlarged upper portion of the diagram of FIG. 80B, with the addition of an example of a mapping of fiber ports 1750 of the first optical fiber connector 1342 and a mapping of fiber ports 1752 of the third optical fiber connector 1346. The mapping of fiber ports 1750 shows the positions of the transmitter fiber ports (e.g., 1753), receiver fiber ports (e.g., 1755), and power supply fiber ports (e.g., 1751) of the first optical fiber connector 1342 when viewed in the direction 1754 into the first optical fiber connector 1342. The mapping of fiber ports 1752 shows the positions of the power supply fiber ports (e.g., 1757) of the third optical fiber connector 1346 when viewed in the direction 1756 into the third optical fiber connector 1346.

[0615] The second optical fiber connector 1344 is designed and configured to be optically coupled to the second co-packaged optical module 1316. The second optical fiber connector 1344 includes optical power supply fiber ports, transmitter fiber ports, and receiver fiber ports. The optical power supply fiber ports provide optical power supply light to the co-packaged optical module 1316. The transmitter fiber ports allow the co-packaged optical module 1316 to transmit output optical signals, and the receiver fiber ports allow the co-packaged optical module 1316 to receive input optical signals. Examples of the arrangement of the optical power supply fiber ports, the transmitter ports, and the receiver ports in the second optical fiber connector 1344 are shown in FIGS. 80E, 89, and 90.

[0616] FIG. 80E shows an enlarged lower portion of the diagram of FIG. 80B, with the addition of an example of a mapping of fiber ports 1760 of the second optical fiber connector 1344 and a mapping of fiber ports 1762 of the fourth optical fiber connector 1348. The mapping of fiber ports 1760 shows the positions of the transmitter fiber ports (e.g., 1763), receiver fiber ports (e.g., 1765), and power supply fiber ports (e.g., 1761) of the second optical fiber connector 1344 when viewed in the direction 1764 into the second optical fiber connector 1344. The mapping of fiber ports 1762 shows the positions of the power supply fiber ports (e.g., 1767) of the fourth optical fiber connector 1348 when viewed in the direction 1766 into the fourth fiber connector 1348.

[0617] The third optical connector 1346 is designed and configured to be optically coupled to the power supply 1322. The third optical connector 1346 includes optical power supply fiber ports (e.g., 1757) through which the power supply 1322 can output the optical power supply light. The fourth optical connector 1348 is designed and configured to be optically coupled to the power supply 1330. The fourth optical connector 1348 includes optical power supply fiber ports (e.g., 1762) through which the power supply 1322 can output the optical power supply light.

[0618] In some implementations, the optical power supply fiber ports, the transmitter fiber ports, and the receiver fiber ports in the first and second optical fiber connectors 1342, 1344 are designed to be independent of the communication devices, i.e., the first optical fiber connector 1342 can be optically coupled to the second switch box 1304, and the second optical fiber connector 1344 can be optically coupled to the first switch box 1302 without any re-mapping of the fiber ports. Similarly, the optical power supply fiber ports in the third and fourth optical fiber connectors 1346, 1348 are designed to be independent of the optical power supplies, i.e., if the first optical fiber connector 1342 is optically coupled to the second switch box 1304, the third optical fiber connector 1346 can be optically coupled to the second optical power supply 1330. If the second optical fiber connector 1344 is optically coupled to the first switch box 1302, the fourth optical fiber connector 1348 can be optically coupled to the first optical power supply 1322.

[0619] The optical cable assembly 1340 includes a first optical fiber guide module 1350 and a second optical fiber guide module 1352. The optical fiber guide module depending on context is also referred to as an optical fiber coupler or splitter because the optical fiber guide module combines multiple bundles of fibers into one bundle of fibers, or separates one bundle of fibers into multiple bundles of fibers. The first optical fiber guide module 1350 includes a first port 1354, a second port 1356, and a third port 1358. The second optical fiber guide module 1352 includes a first port 1360, a second port 1362, and a third port 1364. The fiber bundle 1318 extends from the first optical fiber connector 1342 to the second optical fiber connector 1344 through the first port 1354 and the second port 1356 of the first optical fiber guide module 1350 and the second port 1362 and the first port 1360 of the second optical fiber guide module 1352. The optical fibers 1326 extend from the third optical fiber connector 1346 to the first optical fiber connector 1342 through the third port 1358 and the first port 1354 of the first optical fiber guide module 1350. The optical fibers 1334 extend from the fourth optical fiber connector 1348 to the second optical fiber connector 1344 through the third port 1364 and the first port 1360 of the second optical fiber guide module 1352.

[0620] A portion (or section) of the optical fibers 1318 and a portion of the optical fibers 1326 extend from the first port 1354 of the first optical fiber guide module 1350 to the first optical fiber connector 1342. A portion of the optical fibers 1318 extend from the second port 1356 of the first optical fiber guide module 1350 to the second port 1362 of the second optical fiber guide module 1352, with optional optical connectors (e.g., 1320) along the paths of the optical fibers 1318. A portion of the optical fibers 1326 extend from the third port 1358 of the first optical fiber connector 1350 to the third optical fiber connector 1346. A portion of the optical fibers 1334 extend from the third port 1364 of the second optical fiber connector 1352 to the fourth optical fiber connector 1348.

[0621] The first optical fiber guide module 1350 is designed to restrict bending of the optical fibers such that the bending radius of any optical fiber in the first optical fiber guide module 1350 is greater than the minimum bending radius specified by the optical fiber manufacturer to avoid excess optical light loss or damage to the optical fiber. For example, the minimum bend radii can be 2 cm, 1 cm, 5 mm, or 2.5 mm. Other bend radii are also possible. For example, the fibers 1318 and the fibers 1326 extend outward from the first port 1354 along a first direction, the fibers 1318 extend outward from the second port 1356 along a second direction, and the fibers 1326 extend outward from the third port 1358 along a third direction. A first angle is between the first and second directions, a second angle is between the first and third directions, and a third angle is between the second and third directions. The first optical fiber guide module 1350 can be designed to limit the bending of optical fibers so that each of the first, second, and third angles is in a range from, e.g., 30° to 180°.

[0622] For example, the portion of the optical fibers 1318 and the portion of the optical fibers 1326 between the first optical fiber connector 1342 and the first port 1354 of the first optical fiber guide module 1350 can be surrounded and protected by a first common sheath 1366. The optical fibers 1318 between the second port 1356 of the first optical fiber guide module 1350 and the second port 1362 of the second optical fiber guide module 1352 can be surrounded and protected by a second common sheath 1368. The portion of the optical fibers 1318 and the portion of the optical fibers 1334 between the second optical fiber connector 1344 and the first port 1360 of the second optical fiber guide module 1352 can be surrounded and protected by a third common sheath 1369. The optical fibers 1326 between the third optical fiber connector 1346 and the third port 1358 of the first optical fiber guide module 1350 can be surrounded and protected by a fourth common sheath 1367. The optical fibers 1334 between the fourth optical fiber connector 1348 and the third port 1364 of the second optical fiber guide module 1352 can be surrounded and protected by a fifth common sheath 1370. Each of the common sheaths can be laterally flexible and/or laterally stretchable, as described in, e.g., U.S. patent application Ser. No. 16/822,103.

[0623] One or more optical cable assemblies 1340 (FIGS. 80B, 80C) and other optical cable assemblies (e.g., 1400 of FIG. 82B, 82C, 1490 of FIG. 84B, 84C) described in this document can be used to optically connect switch boxes that are configured differently compared to the switch boxes 1302, 1304 shown in FIG. 80A, in which the switch boxes receive optical power supply light from one or more external optical power supplies. For example, in some implementations, the optical cable assembly 1340 can be attached to a fiber-optic array connector mounted on the outside of the front panel of an optical switch, and another fiber-optic cable then connects the inside of the fiber connector to a co-packaged optical module that is mounted on a circuit board positioned inside the housing of the switch box. The co-packaged optical module (which includes, e.g., a photonic integrated circuit, optical-to-electrical converters, such as photodetectors, and electrical-to-optical converters, such as laser diodes) can be co-packaged with a switch ASIC and mounted on a circuit board that can be vertically or horizontally oriented. For example, in some implementations, the front panel is mounted on hinges and a vertical ASIC mount is recessed behind it. See the examples in FIGS. 77A, 77B, and 78. The optical cable assembly 1340 provides optical paths for communication between the switch boxes, and optical paths for transmitting power supply light from one or more external optical power supplies to the switch boxes. The switch boxes can have any of a variety of configurations regarding how the power supply light and the data and/or control signals from the optical fiber connectors are transmitted to or received from the photonic integrated circuits, and how the signals are transmitted between the photonic integrated circuits and the data processors.

[0624] One or more optical cable assemblies 1340 and other optical cable assemblies (e.g., 1400 of FIG. 82B, 82C, 1490 of FIG. 84B, 84C) described in this document can be used to optically connect computing devices other than switch boxes. For example, the computing devices can be server computers that provide a variety of services, such as cloud computing, database processing, audio/video hosting and streaming, electronic mail, data storage, web hosting, social network, supercomputing, scientific research computing, healthcare data processing, financial transaction processing, logistics management, weather forecast, or simulation, to list a few examples. The optical power light required by the optoelectronic modules of the computing devices can be provided using one or more external optical power supplies. For example, in some implementations, one or more external optical power supplies that are centrally managed can be configured to provide the optical power supply light for hundreds or thousands of server computers in a data center, and the one or more optical power supplies and the server computers can be optically connected using the optical cable assemblies (e.g., 1340, 1400, 1490) described in this document and variations of the optical cable assemblies using the principles described in this document.

[0625] FIG. 81 is a system functional block diagram of an example of an optical communication system 1380 that includes a first communication transponder 1282 and a second communication transponder 1284, similar to those in FIG. 79. The first communication transponder 1282 sends optical signals to, and receives optical signals from, the second communication transponder 1284 through a first optical communication link 1290. The optical communication system 1380 can be expanded to include additional communication transponders.

[0626] An external photon supply 1382 provides optical power supply light to the first communication transponder 1282 through a first optical power supply link 1384, and provides optical power supply light to the second communication transponder 1284 through a second optical power supply link 1386. In one example, the external photon supply 1282 provides continuous wave light to the first communication transponder 1282 and to the second communication transponder 1284. In one example, the continuous wave light can be at the same optical wavelength. In another example, the continuous wave light can be at different optical wavelengths. In yet another example, the external photon supply 1282 provides a first sequence of optical frame templates to the first communication transponder 1282, and provides a second sequence of optical frame templates to the second communication transponder 1284. Each of the optical frame templates can include a respective frame header and a respective frame body, and the frame body includes a respective optical pulse train. The first communication transponder 1282 receives the first sequence of optical frame templates from the external photon supply 1382, loads data into the respective frame bodies to convert the first sequence of optical frame templates into a first sequence of loaded optical frames that are transmitted through the first optical communication link 1290 to the second communication transponder 1284. Similarly, the second communication transponder 1284 receives the second sequence of optical frame templates from the external photon supply 1382, loads data into the respective frame bodies to convert the second sequence of optical frame templates into a second sequence of loaded optical frames that are transmitted through the first optical communication link 1290 to the first communication transponder 1282.

[0627] FIG. 82A is a diagram of an example of an optical communication system 1390 that includes a first switch box 1302 and a second switch box 1304, similar to those in FIG. 80A. The first switch box 1302 includes a vertical ASIC mount grid structure 1310, and a co-packaged optical module 1312 is attached to a receptor of the grid structure 1310. The second switch box 1304 includes a vertical ASIC mount grid structure 1314, and a co-packaged optical module 1316 is attached to a receptor of the grid structure 1314. The first co-packaged optical module 1312 communicates with the second co-packaged optical module 1316 through an optical fiber bundle 1318 that includes multiple optical fibers.

[0628] As discussed above in connection with FIGS. 80A to 80E, the first and second switch boxes 1302, 1304 can have other configurations. For example, horizontally mounted ASICs can be used. A fiber-optic array connector attached to a front panel can be used to optically connect the optical cable assembly 1340 to another fiber-optic cable that connects to a co-packaged optical module mounted on a circuit board inside the switch box. The front panel can be mounted on hinges and a vertical ASIC mount can be recessed behind it. The switch boxes can be replaced by other types of server computers.

[0629] In an example embodiment, the first switch box 1302 includes an external optical power supply 1322 that provides optical power supply light to both the co-packaged optical module 1312 in the first switch box 1302 and the co-packaged optical module 1316 in the second switch box 1304. In another example embodiment, the optical power supply can be located outside the switch box 1302 (cf. 1330, FIG. 80A). The optical power supply 1322 provides the optical power supply light through an optical connector array 1324. Optical fibers 1392 are optically coupled to an optical connector 1396 and the co-packaged optical module 1312. The optical power supply 1322 sends optical power supply light through the optical connector 1396 and the optical fibers 1392 to the co-packaged optical module 1312 in the first switch box 1302. Optical fibers 1394 are optically coupled to the optical connector 1396 and the co-packaged optical module 1316. The optical power supply 1322 sends optical power supply light through the optical connector 1396 and the optical fibers 1394 to the co-packaged optical module 1316 in the second switch box 1304.

[0630] FIG. 82B shows an example of an optical cable assembly 1400 that can be used to enable the first co-packaged optical module 1312 to receive optical power supply light from the optical power supply 1322, enable the second co-packaged optical module 1316 to receive optical power supply light from the optical power supply 1322, and enable the first co-packaged optical module 1312 to communicate with the second co-packaged optical module 1316. FIG. 82C is an enlarged diagram of the optical cable assembly 1400 without some of the reference numbers to enhance clarity of illustration.

[0631] The optical cable assembly 1400 includes a first optical fiber connector 1402, a second optical fiber connector 1404, and a third optical fiber connector 1406. The first optical fiber connector 1402 is similar to the first optical fiber connector 1342 of FIGS. 80B, 80C, 80D, and is designed and configured to be optically coupled to the first co-packaged optical module 1312. The second optical fiber connector 1404 is similar to the second optical fiber connector 1344 of FIGS. 80B, 80C, 80E, and is designed and configured to be optically coupled to the second co-packaged optical module 1316. The third optical connector 1406 is designed and configured to be optically coupled to the power supply 1322. The third optical connector 1406 includes first optical power supply fiber ports (e.g., 1770, FIG. 82D) and second optical power supply fiber ports (e.g., 1772). The power supply 1322 outputs optical power supply light through the first optical power supply fiber ports to the optical fibers 1392, and outputs optical power supply light through the second optical power supply fiber ports to the optical fibers 1394. The first, second, and third optical fiber connectors 1402, 1404, 1406 can comply with an industry standard that defines the specifications for optical fiber interconnection cables that transmit data and control signals, and optical power supply light.

[0632] FIG. 82D shows an enlarged upper portion of the diagram of FIG. 82B, with the addition of an example of a mapping of fiber ports 1774 of the first optical fiber connector 1402 and a mapping of fiber ports 1776 of the third optical fiber connector 1406. The mapping of fiber ports 1774 shows the positions of the transmitter fiber ports (e.g., 1778), receiver fiber ports (e.g., 1780), and power supply fiber ports (e.g., 1782) of the first optical fiber connector 1402 when viewed in the direction 1784 into the first optical fiber connector 1402. The mapping of fiber ports 1776 shows the positions of the power supply fiber ports (e.g., 1770, 1772) of the third optical fiber connector 1406 when viewed in the direction 1786 into the third optical fiber connector 1406. In this example, the third optical fiber connector 1406 includes 8 optical power supply fiber ports.

[0633] In some examples, optical connector array 1324 of the optical power supply 1322 can include a first type of optical connectors that accept optical fiber connectors having 4 optical power supply fiber ports, as in the example of FIG. 80D, and a second type of optical connectors that accept optical fiber connectors having 8 optical power supply fiber ports, as in the example of FIG. 82D. In some examples, if the optical connector array 1324 of the optical power supply 1322 only accepts optical fiber connectors having 4 optical power supply fiber ports, then a converter cable can be used to convert the third optical fiber connector 1406 of FIG. 82D to two optical fiber connectors, each having 4 optical power supply fiber ports, that is compatible with the optical connector array 1324.

[0634] FIG. 82E shows an enlarged lower portion of the diagram of FIG. 82B, with the addition of an example of a mapping of fiber ports 1790 of the second optical fiber connector 1404. The mapping of fiber ports 1790 shows the positions of the transmitter fiber ports (e.g., 1792), receiver fiber ports (e.g., 1794), and power supply fiber ports (e.g., 1796) of the second optical fiber connector 1404 when viewed in the direction 1798 into the second optical fiber connector 1404.