OPTICAL RECEIVING DEVICE USED FOR DARK SOLITON OPTICAL COMMUNICATION SYSTEM

摘要

PROBLEM TO BE SOLVED: To increase the array density of a soliton pulse and to obtain an optical reciever that is used for a very high rate mass optical transmission system by making a return-to-zero digital optical signal and light of constant amplitude incident, converting the light of constant amplitude into an optical pulse signal obtained by inverting the on-off of the return-to-zero digital optical signal and modulating an inverted light pulse signal by means of a phase modulator. SOLUTION: 20G b/s dark soliton optical signal which is subjected to time division four multiplexing and an output of a CW laser 201 are made incident an eclusive-OR optical gate 200 and CW laser beams are converted into a time division multiplex optical signal obtained by inverting the on-off of the dark soliton optical signal. The time division multiplex optical signal is branched into two by an optical coupler 202. A photodetector 203 converts a part of it into an electric signal, a narrow-band filter 204 extracts 20G b/s clock frequency components and a frequency divider 205 converts it into a clock frequency before 5G b/s multiplexing. The other one of a branching optical signal and a 5G b/s clock signal are made incident on an optical demultiplexer 206.