Electronics and Telecommunications Research Institute

Hee-Sang Chung

Jong-Hyun Lee

Kwang-Joon Kim

Sun-Hyok Chang

Ji-Wook Youn

Jin-Soo Han

Won-Kyoung Lee

Moo-jung Chu

Seung-Kwan Kim

A method for realizing, in a fiber amplifier with three stages of amplifiers, automatic gain control in which a constant gain is obtained when channels are varied, and automatic level control in which a constant output per channel is obtained when a light power is varied because of variations in span loss. A light power or another light power of a specific wavelength is monitored to determine when variations in these light powers take place, current values of pump laser diodes appropriate for an input is read from a lookup table, and pump laser diodes are driven. During this operation, a pump power of the first stage amplifier is constantly maintained, and those of the second or third stage amplifier are controlled.

Fiber amplifier and control method thereof

The present invention is to provide an automatic gain-controlled optical fiber amplifier, comprising: a first optical branch for branching a portion of an optical signal inputted into the optical fiber amplifier; a second optical branch for branching a portion of an optical signal outputted from the optical fiber amplifier; an optical distributor for receiving the optical signal of an input side branched partially by the first optical branch and for outputting it separately; a first wavelength selector for receiving the optical signal of a one side distributed by the optical distributor and for selecting a predetermined wavelength optical signal; a second wavelength selector for receiving the optical signal of an output side branched partially by the second optical branch and for selecting the predetermined wavelength optical signal; a signal processor for receiving the optical signal of a second side distributed by the optical distributor and the predetermined wavelength optical signal selected by the first and second optical wavelength selector and for measuring a total power of an input signal and a number of input channels; and a controller for generating a control signal according to the total power of the input signal and the number of input channels measured by the signal processor.

Automatic gain-controlled optical fiber amplifier

Growing community of inventors

Daejeon, South Korea

Hee-Sang Chung