Design and simulation of modified duobinary modulated 40 Gbps 32 channel DWDM optical link for improved non-linear performance

The paper presents a comprehensive analysis of a 40 Gbps Dense Wavelength Division Multiplexing system with 32 channels, spaced at 50 GHz. The design has been optimized for a long haul optical link for Modified Duobinary Return-to-Zero modulation format to establish its superiority over the conventional Duobinary Return-to-Zero format using OptiSystem simulator. The proposed system is designed and tested under perfect dispersion compensation for dispersion management and also with some residual dispersion in the link to mitigate the existing non-linearities. This paper also outlines the superiority of duobinary coding over the conventional non-return to zero modulation with the integration of unequal channel spacing to minimize the Four-Wave Mixing effect. The proposed system has been optimized for a maximum propagation length using different dispersion compensation methods by evaluating the link performance using Q value.