Abstract: In this paper, we have demonstrated the eight channel WDM system using NRZ, RZ and duobinary modulation formats. The WDM system has been analyzed by varying the input power from 0 to 20dBm for different modulation formats in order to find the modulation format for a high data rate optical transmission system. Furthermore, it is found that duobinary modulation is much better than Return-to-Zero and NRZ and the system gives better performance at 40Gbps.

Keywords: Duobinary, Non-return-to-zero, Return-to-zero, Wavelength-division-multiplexing, Quality Factor.