PHASE ADJUSTMENT CIRCUIT, OPTICAL TRANSMISSION DEVICE, AND PHASE ADJUSTMENT METHOD

摘要

A phase adjustment circuit according to the present invention is provided with: an intensity modulation means which modulates the intensity of the input light on the basis of a control signal and outputs intensity-modulated light; a DP-QPSK modulation means which performs DP-QPSK modulation of the output intensity-modulated light and outputs DP-QPSK-modulated light; and a control means which monitors optical intensity of the output DP-QPSK-modulated light and generates and outputs the control signal so that the optical intensity is maximized.