A novel fiber nonlinearity suppression method in DWDM optical fiber transmission systems with an all-optical pre-distortion module

In this paper a novel all-optical scheme is proposed to reduce fiber nonlinear distortions in high-speed dense wavelength division multiplexed (DWDM) optical fiber communication systems by applying time-domain fractional Fourier transform (FRFT) based on the time-space duality theory. The modulated optical pulses will be pre-distorted by an FRFT module before being launched into fiber links. It has been validated that the pre-distorted signal performs better fiber nonlinearity tolerance compared to that without pre-distortion. Simulation results show that the received bit error rate (BER) is improved by several orders of magnitude for a 40 Gbit/s carrier-suppressed return-to-zero on-off keying (CSRZ-OOK) DWDM system, which can be used in a current 40 Gbit/s system easily to improve the nonlinearity effect tolerance.