Electronic post-compensation for nonlinear phase noise in a 1000-km 20-Gbit/s optical QPSK transmission system using the homodyne receiver with digital signal processing

Abstract: We demonstrate electronic post-compensation for nonlinear phase noise in a 1000-km 20-Gbit/s optical QPSK transmission system. Optimized phase shift proportional to intensity noise is given to the homodyne-detected electric field, leading to effective phase-noise reduction.