Long-term nonlinear propagation and damped oscillation behaviors of Gaussian and super-Gaussian pulses in optical fibers

The long-term nonlinear propagation of Gaussian and super-Gaussian optical pulses in the anomalous dispersion regions of optical fibers are investigated numerically in terms of the pulse shapes and spectra evolution. The results show that, both the pulse shapes and spectra exhibit interesting damped oscillation behavior with decreasing oscillation amplitude for very long distance. In particular, the spectra profiles exhibit interesting arrow shaped evolution. Variations of the pulse widths, maximal normalized amplitudes, and maximal spectral amplitudes with the propagation distance, are also presented. We find that, for the higher-order super-Gaussian pulses, their pulse widths and maximal normalized amplitudes have larger values of oscillation periods and initial oscillation amplitudes. However, the higher-order super-Gaussian pulses have larger values of average pulse widths but smaller values of average maximal normalized amplitudes. In frequency domain, the higher-order super-Gaussian pulses have larger values of average maximal spectral amplitudes.