Optical-soliton and chaotic motions in a nonlocal nonlinear medium

Abstract

The coupled equations for the incoherent optical spatial solitons in a nonlocal nonlinear medium is studied analytically. With the soliton solutions hereby obtained via the symbolic computation, the optical-soliton motion in the nonlocal nonlinear medium is studied: is inversely related to , , and , while is positively related to and , but is independent of , with as the slowly varying amplitude of the beam, as the refractive index change, as the beam intensity distribution, as the frequency of the propagating beam, and as the unperturbed refractive index. Head-on and overtaking interactions are observed, and head-on interaction is transformed into an overtaking one with increasing. Bound-state interaction is displayed, and with increasing, the period of decreases, while that of increases. Considering the external forces in the nonlocal nonlinear medium, we explore the chaotic motions in the nonlinear nonlocal medium, including effects of the external forces on such motions. It is seen that when and , the two-dimensional attractors with stretching-and-folding structures are exhibited, and the developed chaos occurs, where and are the amplitudes of external forces, c is the speed of light in vacuum. Such chaotic motions are weakened with , , , and increasing, or with decreasing, where and represent the frequencies of external forces.