Interaction of solitons with bond defects in discrete nonlinear Schrödinger chains.

The interaction of solitons with bond defects in discrete nonlinear Schrödinger (NLS) chains is investigated. A perturbed NLS equation is derived on the basis of a microscopic model. Localized soliton-defect solutions are obtained and their stability is analyzed.

Interaction of solitons with segments with modified dispersion.

The interaction of nonlinear Schrödinger solitons with extended inhomogeneities with modified group-velocity (GV) and group-velocity dispersion (GVD) coefficients is investigated numerically. Increased GVD coefficients act as potential barriers and yield reflection or transmission of the incoming soliton. Decreased GVD coefficients act as potential wells, and for a given range of parameters the scattering results exhibit periodically repeating windows of trapping and transmission as a function of the length of the segment.

Interaction of solitons with extended nonlinear defects.

The interaction of nonlinear Schrödinger solitons with extended inhomogeneities with modified nonlinear coefficients is investigated numerically. Decreased nonlinear coefficients act as nonlinear potential steps and yield transmission or reflection of the incoming soliton. For increased nonlinear coefficients (nonlinear potential wells) and a given range of initial velocities and nonlinearity mismatch, the scattering pattern exhibits periodically repeating regions of trapping and transmission as a function of the length of the inhomogeneity.

Resonant scattering of nonlinear Schrödinger solitons from potential wells.

The interaction of nonlinear Schrödinger solitons with extended inhomogeneities, modeled by potential wells with different shapes, is investigated numerically. For fixed initial velocities below the transmission threshold, the scattering pattern as a function of the width of the well exhibits periodically repeating regions of trapping, transmission, and reflection. The observed effects are associated with excitation and a following resonant deexcitation (in the cases of escape) of shape oscillations of the solitons at the well boundaries.