Fiber-optical data-communication system using carriers of different wavelengths

摘要

A plurality of data-transmitting stations communicate with respective data-receiving stations via channels using optical carriers of different wavelengths, the several channels sharing a common light guide between an optical multiplexer at an outgoing terminal and an optical demultiplexer at an incoming terminal. To minimize cross-talk between channels, the data streams modulating their carriers are so synchronized that the signal peaks appearing beyond the demultiplexer on any pair of spectrally adjacent channels are relatively offset by half a signal period of their data streams or of the faster one of these two data streams. The synchronization can be carried out through electronic control of the channel modulators at the transmitting stations or with the aid of optical delay lines inserted in every other channel upstream of the multiplexer. A similar phase relationship is maintained between incoming and outgoing data streams at a subscriber station having a transmitter and a receiver communicating via an optical duplexer with a single light guide.