Patent ID: 6616351
Filing Date: 2003-09-09
Classification: H04B,H04J

Abstract:
In a bidirectional WDM (wavelength division multiplexing) optical communication network, an optical amplifying apparatus for amplifying an optical input signal to a predetermined level according to an optical output of a pump laser, and outputting an amplified optical output signal, said optical amplifying apparatus comprising:a bidirectional optical amplifier for amplifying a forward WDM optical input signal and a backward WDM optical input signal, and outputting an amplified forward WDM optical output signal and an amplified backward WDM optical output signal, respectively; an optical signal measurement means for measuring a total input intensity of the optical input signal to the optical amplifying apparatus by adding the forward WDM optical input signal and the backward WDM optical input signal, and for measuring a total output intensity of the optical output signal from the optical amplifying apparatus by adding the forward WDM optical output signal and the backward WDM optical output signal; and a control means for calculating an optical gain from the total input intensity and the total output intensity, and feedback-controlling a transmission gain of the bidirectional WDM optical communication network by controlling the output of the pump laser according to the calculated optical gain, and thereby uniformly maintaining the transmission gain of the bidirectional WDM optical communication network.