| 摘要 |
PROBLEM TO BE SOLVED: To provide a stably optical channel output level so as to absorb loss change by an optical output level per optical channel, while avoiding the light output of a retrained optical channel from becoming suddenly abnormally large, even if the number of wavelengths is abruptly changed in a wavelength multiplexing light network, and to provide a high quality stable optical output at each optical channel for increasing or decreasing to install the number of the wavelengths to be branched and inserted. SOLUTION: The wavelength multiplexing optical amplifier for the optical network is made to control with a fixed gain and control variable optical attenuator for changing the light level, without having wavelength dependence. The amplifier always controls at a fixed attenuation amount, and controls to change the attenuation amount so as to obtain a desired optical level under a negative feedback control from an output monitor only when accurate number-of-wavelengths information is input. A wavelength unit branching/inserting unit applies control to the level control of a passing signal light. The branching/inserting unit, having a mechanism for controlling at a constant insertion signal light level without wavelength dependence and a multiplexing mechanism of the inserting light and passing light signal without wavelength dependence increases or decreases to install the optical channel of branching/inserting without on site adjustments. |
