Coupling configuration for optically coupling an optical conductor to an opto-receiver

[0001] The invention relates to a coupling configuration for optically coupling an optical conductor to an opto-receiver.

[0002] When optical glass fibers are connected through the use of a plug-in contact, it is necessary to achieve a very high accuracy when using single-mode fibers (SMF). Since the “active” core of SMF glass fibers measures only a few micrometers in diameter, the fibers in plug-in contacts must be adjusted accurately to a few hundredths of a micrometer in order to achieve good launching of the signal.

[0003] In the case of known connections, use is made of stepper motors (“stepper modules”) that permit the plug-in contact, and thus the fiber end located therein, to be displaced minimally in the x-direction and y-direction. Once the optimum position has been found, the plug-in contact is held fast at that point through the use of fixers. High-precision stepper motors must be used in order to reach the optimum position. Moreover, the optimum position must be determined by a very complicated measuring method (measurement of the receiving eye). That renders the installation of SMFs, and in particular the adjustment of the connecting technology, very complicated. It constitutes one of the main problems in optical network engineering.

[0004] It is accordingly an object of the invention to provide a coupling configuration for optically coupling an optical conductor to an opto-receiver, which overcomes the hereinafore-mentioned disadvantages and at least eliminates the problem of the heretofore-known devices of this general type.

[0005] With the foregoing and other objects in view there is provided, in accordance with the invention, a coupling configuration for optically coupling an optical conductor to an opto-receiver having a coupling end surface. The coupling configuration comprises a concave mirror having a focal point. The concave mirror reflects light emerging from the optical conductor. A deflecting mirror is disposed substantially at the focal point of the concave mirror. The deflecting mirror deflects the light reflected by the concave mirror onto the coupling end surface of the opto-receiver.

[0006] In accordance with another feature of the invention, the concave mirror is, for example, a parabolic or spherical mirror.

[0007] The light emerging from the optical conductor is projected onto the concave mirror in the coupling configuration. This eliminates the necessity of guiding ends of first and second optical conductors onto one another through the use of guide rails. Moreover, “scattered light” emerging from the optical conductor is likewise picked up by the concave mirror, resulting in minimization of losses. The connection therefore no longer requires an adjustment, or does so at least only in a substantially coarse manner. A displacement of the light exit end of the optical conductor is largely immaterial. Due to the focusing properties of the concave mirror, the light emerging from the optical conductor is always focused at the focal point, and thus onto the deflecting mirror. The coupling configuration is therefore advantageously suitable for connecting SMFs where installation is critical.

[0008] Other features which are considered as characteristic for the invention are set forth in the appended claims.

[0009] Although the invention is illustrated and described herein as embodied in a coupling configuration for optically coupling an optical conductor to an opto-receiver, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.

[0010] The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

[0014] Referring now to the figures of the drawings in detail and first, particularly, to FIG. 1 thereof, there is seen a diagrammatically illustrated first exemplary embodiment based on the principle of the “Newton Reflecting Telescope”. More specifically, light (illustrated by dashes) emerging from an SMF 1 is projected onto a parabolic mirror 2 and back from there onto a launching or coupling mirror 3, and launched or coupled by the launching mirror 3 into a receiver fiber 4. In this case, the launching mirror 3 is located exactly at the focal point of the parabolic mirror 2. The receiver fiber 4 then guides launched or coupled light to a receiver diode 5. The SMF 1 shown is part of a wide-area network (WAN).

[0015] A second exemplary embodiment, which is shown in FIG. 2 and is likewise diagrammatically illustrated, is based on the principle of the “Tilted Reflector”. Instead of the parabolic mirror 2 in FIG. 1, use is made of a spherical mirror 6 that is disposed in such a way that the reflected light is not rectoreflected in the direction of the light exit end of the SMF1, but rather the focal point is offset from that direction.

[0016] FIG. 3 is a sectional view illustrating the structure of a coupling configuration 10 in accordance with the principle of the “Newton Reflecting Telescope” according to FIG. 1. The coupling configuration 10 has a housing 11 that preferably is formed of plastic. The SMF 1 is plugged into a first holder 12 which is integrated in the housing 11. An exit surface 14 of the SMF 1 points into a cavity 13 which is present inside the housing 11. The parabolic mirror 2 is fitted on a side of the cavity 13 opposite the exit surface 14. As described with reference to FIG. 1, the launching mirror 3 is disposed at the focal point of the parabolic mirror 2. A second holder 16 for a focusing lens 15 and the receiver diode 5 is provided on a side of the cavity 13 which is situated at the bottom of FIG. 3. In contrast with FIG. 1, in the structure illustrated in FIG. 3 the light is not fed through an optical conductor, but directly to the opto-receiver in the form of the receiver diode 5. The focusing lens 15 is disposed on a light entrance surface of the receiver diode 5. Both the focusing lens 15 and the receiver diode 5 are plugged into the holder 16. Light reflected by the launching mirror 3 is focused by the focusing lens 15 and projected onto the receiver diode 5.

[0017] It is to be noted that the above-described invention is not limited to the exemplary embodiments described, but includes modifications within the scope of the protection defined by the claims.