Automatic gain control in Raman amplifier with multi-wavelength pumps

Automatic gain control method in Raman amplifier with multi-wavelength pumping scheme is presented. Monitoring of several channel power and feedback pump control is used in the gain control method. The condition to minimize the gain deviation is investigated by numerical simulation. Two monitoring channels are necessary to confine gain deviation in ±0.2 dB at two pumps C-band Raman amplifier. In the experiment, gain deviation of 1.5 dB is controlled to 0.2 dB at 38/40 channels drop, and fast suppression of transient gain excursion is achieved.