Patent ID: 7359112

Claim:
A control apparatus for an optical amplifier comprising: an automatic gain control unit for controlling a gain of said optical amplifier to a constant value based on power of incoming light and outgoing light of said optical amplifier and a target gain; an individual band incoming light monitoring unit for dividing a signal wavelength band of the incoming light into at least a first band and a second band, said first band having a tendency of decreasing power of the outgoing light when there is a decrease in the number of signal wavelengths, and said second band being a signal wavelength band other than said first band, including a gain deviation band in which power of the outgoing light varies mainly due to a wavelength deviation of the gain control by said automatic gain control unit, and for monitoring power of the incoming light to said optical amplifier in each of the first and second bands; an individual band signal wavelength number calculation unit for obtaining the number of signal wavelengths in each of the first and second bands based on a result of the monitoring by the individual band incoming light monitoring unit; and a target gain correction unit for correcting said target gain to be used in said automatic gain control unit based on a result of the calculation by said individual band signal wavelength number calculation unit when there is a variation of the number of signal wavelengths.