Analysis of Self Phase Modulation Effect in 40 Gb/s Optical Fiber Communication System for Various Modulation formats with Dispersion Compensation

In this paper the effect of Self Phase Modulation fiber nonlinearity in 40 Gb/s optical fiber communication system has been compared with different modulation formats such as non return to zero (NRZ), return to zero (RZ), carrier suppressed return to zero (CS-RZ) and modified duo binary return to zero (MDRZ). The effect of SPM fiber nonlinearity has investigated in terms of Q-factor at the receiver output by using different modulation formats with variation in input launched power from -10 to 15 dBm. It has observed that the performance of optical fiber communication system is limit by SPM effect and MDRZ format seems to be best choice for input power 15 dBm. Further, we have analysed the effect of SPM in terms of Q-factor with variation in fiber length from 60 to 360 km and observed that at 360 km fiber length MDRZ format gives better Q-Factor as comparison to other modulation formats. So we proposed that MDRZ modulation format will be used when system should operate at high input power and longer distance.