All-optical phase noise suppression using optical nonlinear mixing combined with tunable optical delays

We propose and demonstrate an all-optical scheme of phase noise reduction using optical nonlinearity and dispersion/conversion delay. This scheme is capable of reducing the standard deviation of phase noise with low frequency component (e.g., laser phase noise) by a factor of ~ 4 without degrading the data signal. The EVM can be reduced from 31% to 11% for ~500 MHz phase noise bandwidth on 20-Gbaud QPSK input.