Patent ID: 8295709

Claim:
A dispersion compensation device comprising: a variable dispersion compensator configured to subject an input optical signal to dispersion compensation; an optical receiver configured to convert an optical signal subjected to dispersion compensation into an electrical signal, recover a clock signal and a received data signal from the electrical signal, and output clock lock information indicating whether the clock signal is locked to the electrical signal; a signal processor configured to output bit error rate information on the received data signal; and a controller configured to variably control a dispersion compensation value of the variable dispersion compensator based on the bit error rate information and the clock lock information, wherein the controller identifies a first dispersion compensation value that allows the clock signal to be locked, by performing a search whereby the dispersion compensation value of the variable dispersion compensator is varied successively in a predetermined first step increment, and, afterwards, the controller variably controls the dispersion compensation value in the neighborhood of the first dispersion compensation value, based on the bit error rate information.