Optical wavelength stabilization circuit, optical transmitter and optical transmission system

摘要

In the initial state, any wavelength variation of the output signal light with a change of the current injected into the laser (50) is monitored with a wavelength meter (62), the quantity of wavelength variation is fed back to the wavelength compensation circuit (61), a compensation voltage (Vcomp) for maintaining the wavelength in the initial stage is figured out, and that voltage is recorded into a memory element or the like. A configuration to add this compensation voltage to a comparator (58) makes it possible to compensate for fluctuations of the characteristics of the optical splitter (51), wavelength filter (52) and light receiving elements (PD5,PD6) and thereby to obtain a stable optical wavelength. By constantly monitoring the injected current applied to the laser (50) when the optical transmitter (60) is in operation and giving a compensation voltage matching the current variation to the comparator (58), stabilization of the optical wavelength can be realized. By simulating in the initial state the operation of the laser (50) after deterioration and providing in advance a compensation voltage for suppressing wavelength fluctuations, wavelength fluctuations after deterioration can be restrained.