Four-wave mixing noise in dispersion managed DWDM system including effect of randomly varying birefringence strength and orientation along fiber

► Intensity-modulated/direct-detection dispersion-managed DWDM system is supposed. ► Four-wave-mixing noise for this system is approximately analyzed. ► This analysis includes walk-off between channels. ► Effect of randomly varying birefringence along fiber is included also. ► How dispersion maps effect the random polarization-dependent FWM noise is given.