FDM OPTICAL SYSTEM

摘要

In order to increase the information carrying capacity of an optical fiber communication system, at the transmitting side of the system a reference optical beam and a plurality of closely spaced optical carriers having frequencies which are coherently related to the reference frequency of the reference optical beam are generated and the plurality of closely spaced optical carriers are combined to provide a multiplexed optical output beam. At the receiving side of the system a frequency tracking optical beam tracks the reference optical beam and the plurality of closely spaced optical carriers of the multiplexed optical output beam are optically heterodyne detected by the tracking optical beam to convert the plurality of closely spaced optical carriers into a microwave spectrum, so that the individual carrier frequencies present in the microwave spectrum which correspond to the frequencies of the plurality of closely spaced optical carriers may be electronically heterodyne detected and separated from the microwave spectrum.