A short theoretical study on the XPM frequency limitations in NOLM based wavelength converters

This paper presents a study on the frequency limitations imposed by cross-phase modulation (XPM) in wavelength converters based on nonlinear optical loop mirrors. A novel analytical model is used to demonstrate that the influence of group velocity dispersion ultimately limits the switching speed of such wavelength converters. This limitation is used to define the bandwidth of the XPM-induced phase modulation and relate this with the converter characteristics (conversion ratio and pulsewidth of the converted signal).