On the integrability aspects of nonparaxial nonlinear Schrodinger equation and the dynamics of solitary waves

The integrability nature of a nonparaxial nonlinear Schrodinger (NNLS) equation, describing the propagation of ultra-broad nonparaxial beams in a planar optical waveguide, is studied by employing the Painleve singularity structure analysis. Our study shows that the NNLS equation fails to satisfy the Painleve test. Nevertheless, we construct one bright solitary wave solution for the NNLS equation by using the Hirota's direct method. Also, we numerically demonstrate the stable propagation of the obtained bright solitary waves even in the presence of an external perturbation in a form of white noise. We then numerically investigate the coherent interaction dynamics of two and three bright solitary waves. Our study reveals interesting energy switching among the colliding solitary waves due to the nonparaxiality. (C) 2020 Elsevier B.V. All rights reserved.