| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem of an optical amplifier cannot maintain gain flatness properties, gain deviation is generated over a system tolerance, and hence transmission quality is affected greatly, when the number of signals to be transmitted is equal to or less than half the sum for passing through a transmission path, or the wavelength arrangement of the signals to be transmitted is distributed unevenly, while WDM transmission is made in the transmission path having the optical amplifier. SOLUTION: An inverting distribution fixing signal light source is provided in either equipment or places of an optical transmission apparatus, having an optical amplifier in the transmission line between a transmitter and a receiver, and the operation state of the optical amplifier is locked within the range for maintaining amplification characteristics to a fixed state by an inverting distribution fixing signal generated from the light source, thus flexibly coping with the change in the number of signals and the uneven distribution of wavelength arrangement. |
