Impact of Cross Phase Modulation in Long Haul DWDM Fiber Optic Communication and its Suppression

The explosive growth of the Internet urges the quantum leap in the transmission capacity of the optical fiber network. In long-haul DWDM systems, Cross-phase modulation is the dominant nonlinearity that impairs the system’s performance. Cross-phase modulation (XPM) will turn to intensity modulation by fiber dispersion and will cause the pulse’s distortion. Hence, there is a need to suppress cross phase modulation in order to increase transmission capacity. Optical Phase Conjugation is one of the methods to reduce impairments due to cross phase modulation. Besides intensity modulation, DQPSK modulation is carried out to increase bit rate. The technique presented is the simplest and produces good results for high power laser source. This paper analyses the effect of cross phase modulation in DWDM system and it is experimentally analyzed using OPTSIM (Optical Communication Simulator).