Soliton shaping and conversion for some inhomogeneous nonlinear schrödinger models in optical fiber

Abstract

Optical soliton is one of the foremost discoveries in the history of modern nonlinear Science. Solitons can be applied in particle physics, fluid mechanics, Bose-Einstein condensation and nonlinear fiber optics. Since the first theoretical prediction and experimental demonstration of the optical soliton in a nonlinear fiber, the study of solitons has attracted considerable attention because of their widespread applications in long-distance communications, optical switching devices and pulse shaping. For this reason, optical soliton pulse propagation in various inhomogeneous models which is the main focus of this thesis, has been investigated from different points of view. In a nonlinear fiber, solitons can evolve by choosing appropriate pulse and fiber parameters to obtain a counter balancing of Group Velocity Dispersion (GVD) and Self-Phase Modulation (SPM). In this thesis, to find the soliton solutions for few models of NLS equations, Darboux transformation technique is employed based on the Lax pair of NLS equations. From the theoretical point of view, the propagation of optical soliton in waveguides are represented by the inhomogeneous or non-uniformly medium for various aspect of nonlinear physical phenomena. This thesis provides knowledge about the impacts of inhomogeneous parameters on optical pulses in fiber. We investigate the effects of inhomogeneous parameters on soliton dynamics which reveals that how solitons are affected due to inhomogeneities in the fiber. Due to inhomogeneous fiber systems, the propagation equation and soliton solutions comprise of variable coefficients. By choosing different forms of variable coefficients, such as group velocity dispersion, nonlinearity, different soliton shaping is investigated. newline