Optical signal transmitter and method for controlling polarization multiplexed optical signal

摘要

An optical signal transmitter includes: first outer modulator (10) to generate first modulated optical signal, the first outer modulator (10) including a pair of optical paths and a first phase shifter (11) to give phase difference to the pair of optical paths; second outer modulator (20) to generate second modulated optical signal, the second outer modulator (20) including a pair of optical paths and a second phase shifter (21) to give phase difference to the pair of optical paths; combiner (31) to generate polarization multiplexed optical signal by combining the first and second modulated optical signals; phase controller (56) to control the phase difference by the first phase shifter toA-Ӯ and control the phase difference by the second phase shifter to A+Ӯ; and power controller (55) to control at least one of the first and second outer modulators based on AC component of the polarization multiplexed optical signal.