Pre-dispersed Mutual Phase-conjugation Scheme for Fiber-nonlinearity Mitigation in Coherent Optical Communication Systems - Proposal and Analysis of Parallel Back-propagation Method

摘要

We propose and analyze an effective and practical method for mitigating signal distortion caused by fiber nonlinearity. In the proposed method, an original signal and a pre-dispersed phase-conjugated signal are simultaneously transmitted through the fiber on two polarization modes. The nonlinear distortion is generated in a back-propagation manner on the pre-dispersed phase-conjugated signal and cancels the nonlinear distortion on the original signal transmitted in parallel. Through extensive simulations, we demonstrate that the optimal power of the quadrature phase-shift keying (QPSK) signal is improved by over 7 dB in a 1,000-km-long dispersion-unmanaged link using standard single-mode fibers (SMFs) only.