Impact of optical modulation formats on 10Â G/2.5Â G asymmetric XG-PON system

In this paper, simulative analysis of 2.5 G/10 G asymmetric Passive optical network (XG-PON) system has been carried out for 33% Return-to-Zero (33% RZ), 50% Return- to-Zero (50%RZ) and Carrier Suppressed Return- to-Zero (CS-RZ) modulation formats. The XG-PON system has been analysed by varying fiber length in order to find the optimum modulation format for asymmetric XG-PON optical transmission system. The result has been compared for these modulation formats for downstream and upstream data in terms of Q-Factor and eye opening. It has also been observed that the performance of asymmetric XG-PON system is severely limited by polarization mode dispersion (PMD) and non linear effects and is determined that CS-RZ format provides best performance as compared to RZ modulation format.