Suppression of nonlinear intrachannel interactions between return-to-zero pulses in dispersion-managed optical transmission systems

Abstract

Strong dispersion management, in which an optical pulse is highly dispersed and the pulse width is extremely broadened, can suppress nonlinear interactions such as cross-phase modulation between neighboring pulses in optical time-division-multiplexed systems, but it causes intrachannel four-wave mixing, which is an obstacle to achieving high performance in the system. We study the physical mechanism of intrachannel four-wave mixing. The dependence of the effect on the initial pulse width, the initial phase difference, and the dispersion map is also discussed, and we conclude that a narrower initial pulse, a larger accumulated dispersion, or both are effective in suppressing the effect of four-wave mixing.