Suppression of ghost pulses in 40Gbps optical transmission systems with fixed-pattern phase modulation.

Novel fixed-pattern phase modulation scheme is proposed to suppress the IFWM-induced ghost pulses in 40Gbps RZ optical transmission systems through destructing the interference of the IFWM components in symmetric patterns. More than 3dBm launch power margin is achieved. It is a cost-effective method to improve the performance of 40Gbps RZ systems due to greater nonlinearity tolerance.