Patent ID: 7262903

Claim:
A multiple-wavelength-pumped Raman amplifier that sets and controls arbitrary signal gain and output characteristics for a wavelength-multiplexed signal light, the multiple-wavelength-pumped Raman amplifier comprising a control unit that controls, based on a relational expression associating a first fluctuation amount, a second fluctuation amount, a third fluctuation amount, and a fourth fluctuation amount, two fluctuation amounts from among the first to the fourth fluctuation amounts by determining other two fluctuation amounts in advance, to determine pumping light powers satisfying the relational expression, wherein the first fluctuation amount is an amount of fluctuation in a current signal light power at a signal input end, the second fluctuation amount is an amount of fluctuation in a current pumping light power at a pumping light input end, the third fluctuation amount is an amount of fluctuation in the current signal power at a signal output end, and the fourth fluctuation amount is an amount of fluctuation in the current pumping light power at a pumping light output end.