| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical amplifier, a node device, and an optical communication network system which can accurately monitor and surely control the light power level of a wavelength multiplex signal without increasing the device scale nor being affected by ASE. SOLUTION: An input light signal is branched by an optical branch unit 21 and demultiplexed by a demultiplexer 7 to respective wavelengths, optical detectors 8b1 to 8b16 detect the light power values of respective input light signals, and a detection control circuit 19 detects light power level information and wavelength number information on the respective wavelengths of the input light signals and the output light signal amplified by an optical amplification part 1 is demultiplexed by the demultiplexer 7 to respective wavelengths, optical detectors 8a1 to 8a16 detect the light power values of respective output demultiplexed signals, and a detection control circuit 92 detect light power level information and wavelength number information on the respective wavelengths of the output light signals. Then a control circuit 5 performs control according to the light power level information and wavelength number information on the respective wavelengths of the input light signals and the light power level information and wavelength number information on the respective wavelengths of the output light signals so that the gains of the respective wavelengths at the optical amplification part 1 are held constant. |
