Effect of Chromatic Dispersion on Four-Wave Mixing in WDM Optical Transmission System

Crosstalk due to four-wave mixing (FWM) is the dominant nonlinear effect in long-haul multi-channel optical communication systems which can severely limit system performance. In this paper, we have simulated the effect of chromatic dispersion on FWM using equal and unequal channel spacing in terms input/output spectrum, eye diagram and bit error rate. Results show that the effect of FWM reduces with the increasing dispersion coefficient, but the reduction is more effective for unequal channel spacing than equal channel spacing. But since, such a fiber is difficult to build, it is suggested that the FWM effect can be suppressed with increased flatter dispersion slope and unequal signal space.