Certain bright soliton interactions of the Sasa-Satsuma equation in a monomode optical fiber

摘要

Under investigation in this paper is the Sasa-Satsuma equation, which describes the propagation of ultrashortpulses in a monomode fiber with the third-order dispersion, self-steepening, and stimulated Raman scatteringeffects. Based on the known bilinear forms, through the modified expanded formulas and symbolic computation,we construct the bright two-soliton solutions. Through classifying the interactions under different parameterconditions, we reveal six cases of interactions between the two solitons via an asymptotic analysis. With thehelp of the analytic and graphic analysis, we find that such interactions are different from those of the nonlinearSchroedinger equation and Hirota equation. When those solitons interact with each other, the singular-I solitonis shape-preserving, while the singular-Ⅱ and nonsingular solitons may be shape preserving or shape changing.Such elastic and inelastic interaction phenomena in a scalar equation might enrich the knowledge of solitonbehavior, which could be expected to be experimentally observed.