METHOD FOR STABILIZING OUTPUT OF OPTICAL AMPLIFIER AND OPTICAL AMPLIFIER USING THIS METHOD

摘要

PURPOSE:To flatten output signals for respective channels varying in light wavelength by multiplexing and demultiplexing the electric power of the amplified light of the single channel of the wavelength which is highest in the gain of an optical amplifier, detecting the same and stabilizing the detected output, thereby executing gain control. CONSTITUTION:Only the amplified light of the channel 1 which is highest in the gain of the optical amplifier 1 is demultiplexed and the monitor output branching a part thereof is obtd. in a multiplexer/demultiplexer 2. The output of the multiplexer/ demultiplexer 2 attenuates as the photoelectric power of the channel 1 which is heretofore largest in the output of the optical amplifier 1 is partly demultiplexed. The channel 1 can be matched with the photoelectric power level of other channels by regulating the wavelength demultiplexing ratio. On the other hand, only a part of the photoelectric power of the channel 1 is taken out of the monitor output of the multiplexer/ demultiplexer 2 and is converted to an electric signal by a photoelectric converter 3. The gain of the optical amplifier 1 is so controlled as to obtain the specified output of the photoelectric converter 3 in a gain control circuit 4. The light outputs are flattened for the respective channels in this way.