Patent ID: 8571414

Claim:
An optical transmission device comprising: a variable dispersion compensator to compensate for chromatic dispersion of an optical transmission path transmitting an optical signal and to output the optical signal; a branching unit to branch the optical signal output from the variable dispersion compensator onto a first light path and a second light path; a reproduction unit to receive the optical signal transmitted on the first light path and to reproduce a first electric signal from the optical signal transmitted on the first light path and; a monitor unit, having a higher sensitivity to a variation of the chromatic dispersion than the sensitivity to the variation of the chromatic dispersion of the reproduction unit, to receive the optical signal transmitted on the second light path, perform a reproducing process to reproduce a second electric signal from the optical signal transmitted on the second light path, produce one of a clock signal from the second electric signal or an out-of-synchronism signal indicating that the clock signal may not be produced from the second electric signal, and control the variable dispersion compensator based on the clock signal or the out-of-synchronism signal.