Optical Phase Noise Extraction and Amplification Technique Through Four-Wave Mixing and its Application to Optical Phase Noise Monitoring in (D)PSK Systems

We propose and experimentally demonstrate an optical phase noise extraction and amplification (OPNEA) technique for phase-shift keying (PSK) signals. It could effectively extract and amplify the phase noise carried in the incoming PSK signals. By applying this OPNEA technique to optical phase-noise (PN) monitoring, a 13-dB monitoring dynamic range and a 0.2-dB/degree monitoring sensitivity were achieved. The monitoring performance is effectively improved compared with an optical PN direct-monitoring scheme based on a Mach-Zehnder interferometer.