Patent ID: 6975448

Claim:
An automatic gain controller of an optical fiber amplifier that outputs transient suppressing signals in order to minimize a transient response characteristic, comprising: a first opto-electric conversion unit for receiving and converting into a first group of electrical signals a first portion of optical signals input into the optical fiber amplifier and to output the first group of electrical signals; a second opto-electric conversion unit for receiving and converting into a second group of electrical signals a first portion of optical signals output from the optical fiber amplifier and to output the second group of electrical signals; a transient suppressing unit for generating pulse-type waveforms when a change in channel quantity is generated during monitoring outputs of the first opto-electric conversion unit; a comparing unit for comparing the sum of output signals of the transient suppressing unit and output signals of the first opto-electric conversion unit with output signals of the second opto-electric conversion unit; a controlling unit for outputting pump control signals in response to the output signals of the transient suppressing unit and output signals of the comparing unit; and a first pumping light source unit for supplying pumping light to the optical fiber amplifier in response to the inputting of the pump control signals.