Influence of four wave mixing on modulation format performance under 100 Gb/s data rate

Four-wave mixing (FWM) is undesirable nonlinear effects that can degrade the optical transmission system. Under high data rate, i.e. 100 Gbps, and ultra-long haul distance, the effects of FWM can limit the system performance significantly. In this paper, we have analyzed and evaluated the system performance tolerance to FWM under the impact of effective area variation. The study was conducted in the presence of normal Non-Return-Zero (NRZ) and Return-Zero (RZ) intensity modulation. In addition, the tuning of effective area on FWM has been done with both types of modulation format. It is found that the RZ modulation introduces minimum FWM power up to −79.5dBm at 80µm
²
effective area, while NRZ offers maximum FWM power less than −74 dBm at the same effective area. In the case of system performance with the effective area variation at 80µm
²
, the BER is 1.99×10−92 at received power of −5.809 dBm in normal RZ modulation. However, in the presence of NRZ modulation format the BER was found to be less than 8.49−10
⁻²¹
at −10.77 dBm received powers. Overall, the result indicates that RZ modulation is the suitable choice for high speed transmission distance and optimum bit-error-rate.