Abstract: A bidirectional optical wavelength multiplexing-demultiplexing device comprises a self-focusing lens having an index gradient and situated between the transmission fibre and filtering means and of which the length is such that the spatial separation between the outgoing wavelengths and the return wavelength is maximum, which permits decoupling of the return channel from the outgoing channels.

Abstract: The invention relates to an optical wavelength multiplexer-demultiplexer using optical fibers. For a bidirectional three-channel link with two go channels and one return channel the multiplexer-demultiplexer comprises a chamfered link fiber (30) provided with an interference filter (25) and optically coupled with three intermediate fibers (13, 14, 15). A first intermediate fiber (13) is chamfered and fitted with an interference filter (20) and has an optical axis which intersects the optical axis of the link fiber at a given angle (.theta.), while a second intermediate fiber (14) is coupled to the chamfered fiber, with the filter (20) providing multiplexing and demultiplexing between the two go channels. A third intermediate fiber (15 is applied to the cylindrical wall of the link fiber to receive or tansmit the return channel via the filter (25). The multiplexer-demultiplexer is applicable to optical fiber telecommunication systems.

Abstract: A device for distributing light energy comprises a chamfered inlet fiber (2) which is coupled to a plurality of outlet fibers (3) which are grouped together in a matrix. The coupling is performed by a diffraction grating (5) which is inclined relative to the chamfered inlet fiber at such an angle that the diffracted beam is a parallel beam, and the matrix of outlet fibers is disposed on the path of said outlet beam. Such a device is applicable to optical fiber distribution systems.