Quasi-Real-Time Optical Sampling Scheme for High-Speed Signal Acquisition and Processing

We present a quasi-real-time coherent sampling approach that combines the high-bandwidth and high-fidelity signal acquisition of equivalent-time optical sampling with real-time digital signal processing and equalization algorithms. The quasi-real-time concept enables feasibility studies of optical communication at symbol rates beyond the bandwidth of conventional digitizer approaches. Here we demonstrate the technique using a 107-GBd polarization-division-multiplexed quadrature phase shift keyed signal.