FORMING STABLE NONLINEAR LIGHTGUIDES WITH CROSS-MODULATION SELF-LOCKING OF INCOHERENT SOLITON MODES

This paper discusses a new class of spatially localized soliton soluti ons with bounded energy in the problem of the nonlinear propagation of a light beam along a photorefractive crystal (PRC) with a drift mecha nism of nonlinear response. Solitons of this class correspond to stabl e propagation in the PRC of two or more wave packets (components) that are matched in intensity distribution but incoherent. Their spatial d istributions correspond to simultaneous cross-modulation self-locking of its first-and higher-order modes into the common nonlinear waveguid e formed by them. It is shown that such multicomponent solitons can be implemented and that they are structurally stable both with respect t o collisions and with respect to substantial (more than 10% in intensi ty) stochastic perturbations of their components as they propagate to distances of the order of several diffraction lengths. The paper discu sses the possibility that conjugate polymers, antiferromagnets, and su perconductors can contain unusual states corresponding to the stable p ropagation of two or more mutually incoherent but matched electron wav e packets along conjugate chains or along isolated atomic planes. (C) 1998 American Institute of Physics.