Patent ID: 6359727
Filing Date: 2002-03-19
Classification: H01S,H04B

Abstract:
An optical amplifier for wavelength-multiplexing transmission, comprising:an input-side optical amplifier having a first amplification optical fiber for amplifying input signals and outputting the signals, first pumping means for supplying, to said first amplification optical fiber, first pumping light having power not more than minimum pumping light power at which a gain of said first amplification optical fiber which has received a minimum input level for the largest number of channels in use causes gain saturation for an increase in input signal level beyond the minimum level, and first pumping light control means for controlling said first pumping means so that an amplification gain for each signal in said first amplification optical fiber decreases in proportion to a level increase amount of each input signal; and an output-side optical amplifier having a second amplification optical fiber for amplifying the signals input from said input-side optical amplifier and outputting the signals, second pumping means for supplying second pumping light to said second amplification optical fiber, and second pumping light control means for controlling said second pumping means so that level of each signal output from said second amplification optical fiber becomes a second gain or target output value.