Patent ID: 6865017

Claim:
An optical amplifier comprising: an optical signal input for receiving an input optical signal to be amplified; means for measuring a power of the input optical signal; a pumping laser input for receiving a pumping laser input signal for use in amplifying the input optical signal; means for measuring a power of the pumping laser input signal; a combiner for combining the pumping laser input signal and the input optical signal; an EDFA having an input coupled to the output of the combiner and an output coupled to a splitter, the splitter dividing out a portion of the signal output from the EDFA and attributable to a pump residual power of the pumping laser after amplification by the EDFA; means for measuring the pump residual power; and feedback means for calculating an expected ratio of the pump residual power and the pumping laser input power using data including the power of the input optical signal, determining an actual ratio of the pump residual power and pumping laser input power, and adjusting a current of the pumping laser by comparing the expected ratio with the actual ratio.