| 摘要 |
PROBLEM TO BE SOLVED: To remove natural discharge noise, to improve S/N, to control a gain and to stabilize amplification by amplifying inputted multi-channel multiplex signal light, flattening the gain in accordance with respective channels and amplifying signal light which is gain-flattened. SOLUTION: A multi-channel optical fiber amplifier is composed of a primary amplification part 100, a gain flattening part 110 and a secondary amplification part 120. Multiplex signal light passes through a first wavelength division/ multiplex coupler 104, travels in the same direction and is amplified to the high gain by an excited first erbium doping optical fiber (E) 106. Different signals by individual channels are outputted from an optical wavelength demultiplexer 112 through the different optical fibers and they are inputted to EDF parts 114a-n of different lengths. Since different damages occur in the signals, the gains by individual channels are flattened and signal light is multiplexed and transmitted in a multiplexer 116. Signal light is amplified again through second EDF 122 so that the high gain is obtained. |
