| 摘要 |
PROBLEM TO BE SOLVED: To provide a means for not degrading the transmission quality of an optical wavelength multiplex system even in the case that a wavelength multiex number is small while suppressing the increase of initial investment. SOLUTION: In this optical wavelength multiplex system capable of the wavelength multiplex of 16 waves at maximum, in the case that only a part of the wavelengths is used in the operation of a construction initial stage, the level of optical signals per wavelength becomes too high by the action of a light amplifier. It causes the waveform degradation of the optical signals or the like by a nonlinear effect in a transmission line or the like and causes the degradation of the transmission quality. It is because that the system is constructed on condition that the wavelength multiplex is performed for 16 waves. Then, in the case that only a part of 16 waves is used as a signal wavelength, the light of the wavelength λc different from the signal wavelength is transmitted together with the optical signals and the total level of the light propagated through the transmission line is turned to the same level as the case of performing the wavelength multiplex of 16 waves. Thus, the level of the optical signals of the respective wavelengths is appropriately adjusted. |
