| 摘要 |
<p>An optical filter (140) has a loss spectrum such that the inclination dL/dμ of the loss L (dB) to the wavelength μ (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/dμ based on the power.</p> |
