Effect of four-wave mixing on the loss budget of four-channel multiplexing NG-PON systems. Issue 1 (2nd January 2021) - Xu, Yan
Abstract : In this study, the loss budget for adopting non-return-to-zero (NRZ) and four-level pulse amplitude modulation (PAM4) in next-generation passive optical networks (NG-PONs) was investigated by simulation and experiment. Through simulation, the signals are distorted by four-wave mixing (FWM) when the zero-dispersion wavelength locates in the middle of the channels. For 25-Gb/s NRZ, a maximal loss budget of approximately 32.5 dB is obtained. For 50-Gb/s PAM4, the bit error rate cannot reach 1 × 10 −3 . While, the impact becomes negligible whens the zero-dispersion wavelength stays away from the middle of the channels, and the loss budget is 36 and 25.7 dB for NRZ and PAM4 systems. Therefore, at least a 32.5-dB loss budget ise obtained in a 4 × 25G NRZ system. While, the loss budget cannot reach the basic requirement of 29 dB in the 4×50G PAM4 system. The experimental resultso verify this conclusion.