| 摘要 |
PROBLEM TO BE SOLVED: To control signal light power of a semiconductor optical amplifier at a predetermined level, without reference to the level of the light power of input light and the wavelength of the input light. SOLUTION: The semiconductor optical amplifier 1 generates different noise light power according to the wavelength of the input light and a driving current. An optical coupler 2 branches a portion of output light of the semiconductor optical amplifier 1 and outputs it to a detector 3. The detector 3 detects the light power of the output light of the semiconductor optical amplifier 1 which has been branched by the optical coupler 2. A control circuit 4 outputs the driving current of the semiconductor optical amplifier 1 based upon the light power detected by the detector 3 so that the output light power of the semiconductor optical amplifier 1 reaches the power obtained by adding the noise light power to target signal light power. COPYRIGHT: (C)2010,JPO&INPIT |
