143 On Post-Compensating Fiber Nonlinearity for Coherent Optical OFDM Network Transmissions

A novel compensation scheme is proposed to reduce the fiber nonlinearity effect for coherent optical orthogonal frequency division multiplexing (CO-OFDM) system. We show that self-phase modulation (SPM) is mitigated with a simple intensity-dependent phase-modulation. A phase modulator is used to modulate the phase of the local oscillator at the coherent receiver. Thus, the nonlinear phase noise induced by amplitude fluctuation and SPM is partially cancelled by coherent detection algorithm. The suggested compensation method is evaluated using numerical simulations and validated in a 10 Gbit/s 4-QAM CO-OFDM system.