Small-signal analysis of wavelength converters based on cross-phase Modulation in dispersion-shifted fibers

In this letter, a closed expression models the wavelength conversion efficiency based on cross-phase modulation in dispersion-shifted fibers and optical filtering. The expression provides the optimum fiber length as well as the wavelength-converter modulation and optical bandwidths. Performance of the technique depending on the characteristics of the filter employed for the phase-to-intensity conversion is also modeled by the expression. A good adjustment between theory and numerical results is obtained, mainly limited by the influence of the first- and second-order dispersion coefficients at high modulation frequencies and fiber lengths.