Abstract
Using the Differential Phase Q (DP-Q) and the traditional Q factor, performance comparison of RZ-OOK and RZ-DPSK in dense OTDM-WDM systems is obtained in this chapter. When signal pulse widths and optical filter bandwidths are optimized, there is no upper limit to WDM channel bit rate (BR) in the purely linear back-to-back configuration. Here, RZ-DPSK performed increasingly better than RZ-OOK in higher spectral density with Q gain increasing from 3 dB to 5 dB. In the nonlinear point-to-point configuration, higher BR leads to increased performance penalties for both RZ-DPSK and RZ-OOK, while RZ-DPSK still outperforms RZ-OOK by up to 4 dB. The results obtained correlate with conventional results, indicating the potential of the DP-Q as a performance evaluation tool in numerical simulations.