Performance Investigation of Hybrid Optical CDMA/ DWDM System Under the Influence of FWM

The significance of nonlinear effects arising from inter- and intra-channel four-wave mixing (FWM) in a hybrid optical code-division multiple-access (OCDMA) and wavelength division multiplexing (WDM) network is thoroughly investigated in this research. The Electro-Optic Phase Modulator (EOPM) module, a crucial component introduced to the system to introduce a phase shift of an ideal value of 2π/3 between adjacent bits, takes center stage. Furthermore, it was discovered that compressing the code sequence into a quarter of the bit duration reduces inter-symbol interference (ISI) and enhances system performance for optical CDMA users. In this investigation, a Multi-diagonal (MD) code is employed as the optical signature sequence code. Even at a high-power level of 18 dBm, the proposed system effectively mitigated the nonlinear effects of inter- and intra-channel FWM. The entire system's performance aligns consistently with both theoretical predictions and simulation results, demonstrating excellent performance for all optical CDMA users.