OPTICAL AMPLIFIER AND OPTICAL AMPLIFYING METHOD

摘要

An optical filter (140) has a loss spectrum such that the inclination dL/d lambda of the loss L (dB) to the wavelength lambda (nm) is variable in the wavelength range of multiplexed signal light. A control circuit (150) measures the power of the signal light branched by an optical coupler (130), controls the power of the pumping light fed from pumping light sources (121, 122) to optical amplifying units (111, 112) based on the measured power of the input signal light so that the measured power may be a certain target value, and controls the inclination dL/d lambda based on the power.