Patent ID: 7061668

Claim:
A gain control circuit for an optical amplifier, comprising: a subtractor which outputs an error signal based on a difference between an input power signal and an output power signal of the optical amplifier; a regulator which generates a bias and correction signal that reduces the error signal to at least substantially zero, the regulator including: an amplification signal path which amplifies the error signal by a desired amplification factor; the amplification signal path including: a differentiator which differentiates the error signal; a multiplier which multiplies the differentiated error signal by said desired amplification factor; and an integrator which integrates the multiplied signal from the multiplier; an integration signal path which integrates the error signal; and an adder circuit which adds the amplified error signal from the amplification path and the integrated error signal from the integration path to form the bias and correction signal; and an adder which adds the input power signal and the bias and correction signal to form a pump control signal which maintains a desired gain of the optical amplifier.