COHERENT OPTICAL COMMUNICATION DEVICE

摘要

PURPOSE:To eliminate the adverse effect of the waveform distortion due to the carrier effect of the high frequency side and thermal effect of the low frequency side of a semiconductor laser when the optical signal in which a semiconductor laser modulation is performed for a code signal is received by an optical receiver. CONSTITUTION:An intermediate frequency signal in which an optic/electric conversion is performed for the local oscillation laser 6 of an optical heterodyne receiver 5 is made to input and by means of AFC(automatic frequency control circuit) 10 having the operating frequency band which is wider than the minimum sensitivity frequency fs of the semiconductor laser 3 of a transmission side, a negative feedback control loop controlling a local oscillation laser 6 is provided. Thus, the transmission and reception of data with high reliability becomes possible.