Patent ID: 7340164

Claim:
An optical wavelength division multiplex transmission system for transmitting optical signals on a plurality of wavelength channels, said system having a transmitting terminal and a receiving terminal interconnected by a transmission line with at least one, optical amplifier, each of optical amplifier comprising: a Raman amplifier with at least one pump light source for pumping the transmission line upstream of the optical amplifier, a controller controlling at least one operation parameter of the Raman amplifier, a single tap coupler arranged downstream of the Raman amplifier, and an optical receiver and transmitter connected to the transmission line for communication of data between at least the transmitting terminal and the optical amplifiers on an optical supervisory channel, at least said optical receiver being operatively connected with the controller to control the at least one parameter of the Raman amplifier in accordance with said data, wherein said optical receiver and said optical transmitter are connected to the transmission line by means of the single tap coupler.