Mitigation of fiber linear and nonlinear effects in coherent optical communication systems

Fiber dispersive and nonlinear effects lead to signal distortions in a fiber optic link, which limits the transmission performance and system capacity. Digital and optical techniques have been proposed to mitigate propagation impairments. In this paper, we give a brief review of digital and optical nonlinear compensation techniques. Then, we present our recent results on three techniques: perturbation-based digital compensation, correlated digital back propagation (DBP), and optical back propagation (OBP). The OBP scheme using dispersion-decreasing fiber is successfully applied to a fiber optic system with mesh configuration and showed 9.8 dB Q-factor gains as compared with the conventional DBP scheme.