A particle-like model for soliton propagation in optical lattices

Abstract

We present a simplified model for describing the propagation of optical solitons through optical lattices. A pair of second order differential equations for the transverse coordinates of the intensity centroid of the soliton are deduced from the nonlinear Schrödinger equation. As an advantage over the quasiparticle approach we avoid the need of integrating algebraically the soliton intensity profile over the lattice. This allows modeling soliton motion even for non-symmetric lattice potentials, as that presented by an outer ring of a modulated Bessel lattice . We discuss in detail the range of applicability of our model and use it to predict the soliton motion in optical lattices generated by plane-waves, Bessel beams, and others.