Multi-channel phase regeneration of QPSK signals based on phase sensitive amplification

In this paper,we propose and demonstrate simultaneous phase regeneration of four different channels of QPSK signal based on phase sensitive amplification.The configuration can be divided into two parts.The first one uses four wave mixing in high nonlinear fiber(HNLF)to generate the corresponding three harmonic conjugates precisely at the frequency of the original signals.The other one uses optical combiner to realize coherent addition which is aimed at completely removing the interaction in phase regeneration stage.The simulation results suggest that this scheme can optimize signal constellation to a large extend especially in high noise environment.Besides,optical signal to noise ratio(OSNR)can improve more than 3 dB while the bit-error-rate(BER)reaches 10 – 3 with a constant white noise and 15° phase noise.