TRANSMITTER AND METHOD FOR GENERATING MULTI-FORMAT AND MULTI-RATE OPTICAL SIGNAL, AND METHOD FOR ASSIGNING MULTI-FORMAT AND MULTI-RATE OPTICAL SIGNAL FLEXIBLY

摘要

PROBLEM TO BE SOLVED: To provide a transmitter and a method for generating a multi-format and multi-rate optical signal without using an electrical multi-level encoded signal or a hybrid integrated optical circuit of a silica planar light-wave circuit and a LiNbOphase modulator, and to provide a method for assigning a multi-format and multi-rate optical signal flexibly.SOLUTION: A transmitter includes a dual drive Mach-Zehnder modulator for modulating an optical signal with some symbols of 8QAM or 16QAM, a dual parallel Mach-Zehnder modulator for modulating an optical signal by BPSK or QPSK, and control means for generating a drive signal for driving the two modulators according to modulation type. An optical communication system including the transmitter assigns flexibly the modulation format and rate of an optical signal based on the signal quality.