Decay of Higher Order Solitons in the Presence of Dispersion, Self-steeping & Raman Scattering

Abstract

The decay of higher order solitons in optical fiber by the influence of the Dispersion, Raman Scattering & Self steeping nonlinear susceptibilities is theoretically analyzed. This influence on the dynamics of optical solitons decay is explored theoretically and experimentally. We have taken into account higher-order dispersion, the shock (self-steepening) term, and a term describing the Raman self-pumping of an ultra short pulse. We study the decay of higher order solitons in optical fibers. The effect of self-steepening, dispersion & Raman scattering on higher-order solitons is remarkable in that it leads to breakup of such solitons into their constituents, a phenomenon referred to as soliton decay. In this phenomenon, the two solitons gets separated from each other within a distance of two soliton periods and continue to move apart with further propagation inside the fiber. It is shown that the Raman Effect is dominant on a femtosecond time scale and leads to the decay of higher-order solitons. For the case of the N = 2 soliton an intense pulse at a distinctly Stokes-shifted frequency is created. This pulse eventually shapes into a fundamental soliton, and its further evolution is governed by the combination of dispersion, self-phase modulation, and the soliton self-frequency shift. The theoretical results are in good quantitative agreement with the recent experiments.