Properties of spatial optical solitons to different degrees of nonlocality

The propagation of optical beams in nonlocal nonlinear media is modeled by the nonlocal nonlinear Schrodinger equation. In this paper, discussed is the propagation properties of the optical spatial solitons in the media to different degrees of the nonlocality. An iteration algorithm based on the split-step Fourier method is presented to obtain the solutions of the solitons. The profiles of the solitons to different degrees of the nonlocality are numerically obtained in the assumption that nonlinear response of the media is Gaussian. The stability of the solutions is also demonstrated numerically, which shows that the stable solitons can survive to different degrees of nonlocality. The amplitude profiles of the soliton transit gradually and continuously from a Gaussian function in the strongly nonlocal case into a hyperbolic secant function in the local case. The critical power for the solitons decreases as the nonlocality decreases. The weaker the nonlocality, the slower the soliton phase that has a linear relation with the propagation distance increases.