| abstract |
A method and apparatus for amplifying an optical signal in an optical network is provided. In an embodiment of the present invention, an optical amplifying module is disclosed for use in an optical network. The optical amplifying module comprises a variable optical attenuator (VOA), an optical amplifier and a controller. The VOA, optical amplifier and controller are coupled to each other and the optical network. The VOA attenuates the optical input signal to produce an attenuated output signal. The optical amplifier amplifies the attenuated output signal to produce an amplified output signal. The controller receives network operating parameters and also monitors the power levels of the attenuated and amplified signals. Based on the measured power levels and the received operating parameters, the controller adjusts the VOA such that the optical output power per channel is maintained at a constant value. The overall gain flatness of the entire system is maintained over a wide range of input powers and a wide range of number of channels in a multi-wavelength system. |