The efficient clock-extraction methods of NRZ signal for chromatic dispersion monitoring

Clock-frequency component (CFC) is widely used to monitor chromatic dispersion. However, the CFCs extracted by different clock-extraction (CE) methods show different characteristics about dispersion. We compare the CE methods of nonreturn-to-zero signal for chromatic dispersion monitoring. We also compare the ability of the CE methods to detect the optimum amount of dispersion compensation when optical nonlinearity exists. As a result, we find out the efficient CE methods to monitor the optimum amount of dispersion compensation in the real high-speed transmission systems.