Evolution of chirped pulses in nonlinear single-mode fibers

Abstract

Computer studies of the evolution of pulses in nonlinear single-mode fibers are presented. In the case of anomalous dispersion, the time-bandwidth product of the initial pulse is varied by imposing a linear frequency chirp. The pulse broadening resulting from chirp greatly exceeds the broadening caused by the loss. In the case of normal dispersion the evolution of an initially unchirped pulse is shown to depend critically on the loss. This fact is explained by the position of the chirp's maxima and minima relative to the pulse-amplitude distribution.

Nonlinear pulse reshaping in passive optical fibers towards quasi-parabolic waveforms

“…Although these results were obtained in the case of small soliton number (up to [4][5], where optical wave breaking is weak, the same nearly parabolic pulse shape in the far field of dispersion one can observe in the case of much higher soliton number (~ 30), where optical wave breaking is fully evident. The optical wave breaking establishing was extensively investigated as mentioned above, but the optical wave breaking cancellation is not known.…”

“…Because of a large amount of the SPM-induced frequency chirp imposed on the pulse, even weak dispersive effects lead to significant pulse reshaping. For the first time a pulse evolution resulted in the establishing of optical wave breaking was investigated by Lassen et al 5 and Tomlinson et al 6 . Since then this phenomenon is well understood.…”

“…Particularly the propagation in the normal dispersion regime at high-power is subject to instability through the appearance of the optical wave breaking on the temporal pulse envelope as it was observed experimentally [2][3][4] . This effect was extensively investigated numerically [4][5][6] and analytically [7][8][9] . It was found that a parabolic pulse with a linear chirp can propagate without wave breaking 8 .…”

Evolution of solitons from chirped and noisy pulses in single-mode fibres

“…where cp (real) is denoted the chirp parameter [6]. Opposite chirps, 0 and ^(f) say, correspond to complex conjugate pulses, and complex conjugation of eqns.…”

“…An earlier publication [6] dealt with pulses having a linear chirp, which may be a reasonable model for pulses generated by semiconductor lasers [7]. The evolution of the pulse for different chirp parameters was studied.…”