Compensation of nonlinear self-phase modulation with phase modulators

The compensation of the nonlinear self-phase modulation of a 10 Gbit/s RZ data stream with phase modulators has been experimentally demonstrated. The electrical waveform that drives the phase modulators is synthesised from the recovered 10 GHz clock and its 20 GHz harmonic. The method is broadband, polarisation insensitive and allows nearly arbitrary control of the magnitude and sign of the nonlinear phase compensation.