Nonautonomous Solitons for the Coupled Variable-Coefficient Cubic-Quintic Nonlinear Schrödinger Equations with External Potentials in the Non-Kerr Fibre

Abstract

AbstractVariable-coefficient nonlinear Schrödinger (NLS)-type models are used to describe certain phenomena in plasma physics, nonlinear optics, arterial mechanics, and Bose–Einstein condensation. In this article, the coupled variable-coefficient cubic-quintic NLS equations with external potentials in the non-Kerr fibre are investigated. Via symbolic computation, similarity transformations and relevant constraints on the coefficient functions are obtained. Based on those transformations, such equations are transformed into the coupled cubic-quintic NLS equations with constant coefficients. Nonautonomous soliton solutions are derived, and propagation and interaction of the nonautonomous solitons in the non-Kerr fibre are investigated analytically and graphically. Those soliton solutions are related to the group velocity dispersionr(x) and external potentialsh1(x) andh2(x,t). With the different choices ofr(x), parabolic, cubic, and periodically oscillating solitons are obtained; with the different choices ofh2(x,t), we can see the dromion-like structures and nonautonomous solitons with smooth step-like oscillator frequency profiles, to name a few.