DPSK MODULATION/DEMODULATION METHOD, AND OPTICAL COMMUNICATION DEVICE AND SYSTEM USING THE METHOD

摘要

Provided are an optical communication device and an optical communication system using an inexpensive and small-sized DPSK modulation of a low power consumption. An N:1 multiplexer (125) creates a serial signal by time-division multiplexing parallel signals encoded by DPSK modulating encoders (115 - 117), for every bits. An electric - phase modulation optical signal converter (127) converts the serial signal into a phase-modulated light. An N-bit delay interferometer (132) subjects the phase-modulated light to a DPSK demodulation by comparing it with an optical signal of N bits ago. An optical-electric signal converter (134) converts the decoded intensity-modulated light into an electric signal. An N:1 demultiplexer (136) divides the electric signal converted by the optical-electric signal converter (134), into N signals by the time division for every bits.