Abstract: In this paper, the 32 channel WDM system at 20 Gb/s has been investigated for the different channel spacing. The performance has been analyzed on the basis of dispersion. The comparison of BER, Q-factor and eye opening for WDM and DWDM systems at different dispersion is done. It is observed that at different dispersion 2-10 ps/nm/km the 32 × 20 Gb/s WDM system provides better results than the 32 × 20 Gb/s DWDM (dense wavelength division multiplexing) system in the presence of nonlinearities. The analysis is done using OptiSystem 7.0 simulator.

Keywords: WDM, DWDM, BER, EDFA, Q Factor, Eye height, OptiSystem 7.0