Triple fibre amplifier with transient, automatic control of amplification or signal height and detection of input signal height

摘要

A method for realizing, in a fiber amplifier with three stages of amplifiers (100,200,300), automatic gain control (530) 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 (L1) or another light power of a specific wavelength is monitored (520) 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 (540), and pump laser diodes are driven. During this operation, a pump power of the first stage amplifier (100) is constantly maintained, and those of the second or third stage amplifier are controlled (530). IMAGE