| 摘要 |
PROBLEM TO BE SOLVED: To compensate the gain change of an optical amplifier, to reduce a distortion and a crosstalk in a saturation area and to improve transmission efficiency and quality by introducing a reservoir optical channel having a prescribed wavelength into a communication route. SOLUTION: In a wavelength division multiplex system 400, a laser beam source 410 and a 3 dB coupler 411 or the like are utilized and the channel is inputted before the first semiconductor optical amplifier 421 of a transmitting part 420. The reservoir channel is positioned in the signal band of the optical amplifier 421, positioned in the wavelength in a spectrum in the neighborhood of the max. point of the min. point of gain change and made to be higher than a traffic channel in an initial strength level. Then gain change is reduced and the strength is shared with another channel in accordance with the change of an input strength. Thus, the channel is functioned as a reception compensating mechanism so that gain change caused by a strength fluctuation in the input of the optical amplifier, for example, the addition or erasion of the traffic channel is suppressed. |
