On Mitigation of Four-Wave Mixing in High Capacity Ultra-DWDM System

Due to the excessive demand on multimedia, the network traffic requires new technologies to improve communication networks. The core data networks are formed of single and multichannel fiber optical transmission systems nowadays. The leading technology in a multichannel fiber optical communication is 10 Gbps DWDM (Dense Wavelength Division Multiplexing), which is used worldwide. The 40 Gbps DWDM systems are still in the adaptation phase. The development of DWDM system increases the transmission speed, transmission distance and channel traffic. On the other hand, the multichannel transmission over single optical fiber induces nonlinear effects which degrades performance of DWDM system. The four-wave mixing (FWM) is the most dominant of all nonlinear effects, especially in dense division multiplexing systems. FWM appear as a crosstalk between the adjacent channels in DWMD system. In this paper we propose a strategy to mitigate the impact of FWM on optical signal transmission in a DQPSK modulated 32-channel Ultra-DWDM system with 1.28 Tbps (40 Gbps per channel) transmission capacity. The simulation model is based on the ITU-T G.694.1 and created in OptiSystem™ software. The resulting signal is mathematically analyzed and BER and Q factor values are calculated.