| 摘要 |
PROBLEM TO BE SOLVED: To control light intensity at every light signal of a multiplex wavelength to be constant by receiving a wavelength multiplex signal obtained by complexing and multiplexing the light signals of different wavelengths, multiplexing and amplifying the plurality of demultiplexed light signals of the different wavelengths, detecting the multiplex number of the plurality of light signals of the different wavelengths and controlling the output light intensity of an optical amplifier so that it corresponds to the number. SOLUTION: A wavelength multiplex signal Ss received from an outer device is demultiplexed into the four waves of the light signals of wavelengths λ1 to λ4 by a wavelength demultiplex device 1. Part of the light signal of the wavelength λ1 is sent to a light detection device 4(1) by an optical demultiplex device 2(1). The remaining part is sent to a wavelength multiplex device 3. Part of the light signal of the wavelength λ2 is transmitted to a light detection device 4(2) by an optical demultiplexer 2(2) and the remaining part is transmitted to the wavelength multiplex device 3. A controller 5 refers to a control table held inside by itself and controls the constant output of an optical amplifier 7 in a four wave multiplex state. |
