DRIVING VOLTAGE CONTROL METHOD, DRIVING VOLTAGE CONTROL PROGRAM AND DRIVING VOLTAGE CONTROL DEVICE FOR MACH-ZEHNDER TYPE OPTICAL MODULATOR, AND OPTICAL TRANSMISSION DEVICE

摘要

PROBLEM TO BE SOLVED: To shorten an operation time and to reduce the cost, and to keep the quality of a transmitted optical signal constant by automatically setting the amplitude Vp of a driving voltage of a Mach-Zehnder type optical modulator to an optimum value V_π irrelevantly to a bias voltage Vb.;SOLUTION: Provided are an optical detection part 18 which detects the mean power of output light, a signal processing part 19 which outputs a bias voltage control signal and a driving voltage control signal of the Mach-Zehnder type optical modulator 14 by processing the output signal of the optical detection part 18 as specified, a bias voltage control part 20 which applies a bias voltage to the Mach-Zehnder type optical modulator 13, and a driving voltage control part 21 which applies the driving voltage to the Mach-Zehnder type optical modulator 14. After the driving voltage at which the quantity of variation in the mean power becomes less than a specified value is found when the bias voltage is sequentially varied, the driving voltage is applied to the Mach-Zehnder type optical modulator 14 according to a data signal to modulate laser light, whose modulated laser light is sent out.;COPYRIGHT: (C)2005,JPO&NCIPI