Patent ID: 8564878

Claim:
An optical amplifier comprising: a semiconductor optical amplifier; a first power monitor configured to monitor an optical power of an out-of-signal-band noise output from the semiconductor optical amplifier; a corrector configured to correct a relationship between a driving current for the semiconductor optical amplifier and a noise optical power based on the out-of-signal-band noise optical power monitored by the first power monitor, wherein the corrector corrects target total output optical power obtained by adding target signal output optical power to an out-of-signal-band noise optical power corresponding to the driving current using a correction coefficient, and a second power monitor configured to monitor total output optical power of light output from the semiconductor optical amplifier; and a driver configured to control the driving current based on results of a comparison between the target total output optical power corrected by the corrector and the total output optical power monitored by the second power monitor.