High-resolution measurement and spectral overlap of cross-phase modulation induced spectral broadening

Cross-phase modulation induced spectral broadening in WDM systems is measured using a high-resolution optical spectrum analyzer. The measured spectra are consistent with recently developed theoretical models. Using the theoretical models, the spectral overlap between two adjacent WDM channels is estimated for a typical 10-Gb/s system having 50 GHz of channel spacing. For -20 dB overlap, the product of number of fiber spans and optical power per channel must be less than 18.1 and 15.5 dBm for standard and nonzero-dispersion-shifted fiber, respectively.