Effective Phase Noise Suppression in Externally Injected Gain Switched Comb Source for Coherent Optical Communications

Abstract

We investigate the residual phase noise in an injected gain switched comb source with FMnoise spectrum analysis, and examine the impact of this noise on the performance of a DQPSK system at 10.7GBaud. A 2dB penalty exists for the 10 line comb source due to the excess phase noise, and the penalty can be eliminated by optimized injection.