Novel Polarization-diversity Scheme Based on Mutual Phase Conjugation for Fiber-nonlinearity Mitigation in Ultra-long Coherent Optical Transmission Systems

We propose a novel method of fiber-nonlinearity mitigation for ultra-long optical transmission systems, which employs two polarization modes mutually phase-conjugated. Simulations and experiments show that in the nonlinear region, this diversity method significantly outperforms both of the singleand dual-polarization schemes at the same bit rate.