All-Optical Highly Sensitive Chromatic Dispersion Monitoring Method Utilizing Phase-Matched Four-Wave Mixing

This letter represents a highly sensitive all-optical chromatic dispersion (CD) monitoring method utilizing phase-matched four-wave mixing (FWM) in highly nonlinear optical fibers (HNLFs). The monitoring ability arises from the exponential FWM gain which provides an exponential power transfer function (PTF) mapping the CD experienced by the signals onto the average power of the output idler wave. Our method is simple and much more sensitive compared to the other PTF-based monitoring methods proposed before. The sensitivity enhancement is important for highly accurate dispersion compensation and makes the method effective for signals with high duty cycles. Furthermore, by tailoring the phase-matched wavelength range our method can be used to monitor CD in a wavelength-division-multiplexing (WDM) network.