Optically amplified gain control circuit and optically amplified gain control method

摘要

An optically amplified gain control circuit is disclosed, which comprises an optically amplifying medium for amplifying an optical signal, a exciting light coupler for combining exciting light with the optical signal optically amplified by the optically amplifying medium, and a control circuit for controlling an output of the exciting light combined with the optical signal by the exciting light coupler, wherein the optical signal to be amplified is composed of a main signal, an SV signal, and a tone signal which are multiplexed, and wherein the control circuit controls the output of the exciting light corresponding to the tone signal on the preceding stage of the optically amplifying medium and the tone signal on the next stage of the optically amplifying medium so as to control the amplification of the optical signal by the optically amplifying medium.