Few-cycle solitons in a quasiequilibrium nanodispersed medium of asymmetric molecules

Abstract

The nonlinear dynamics of extremely short electromagnetic pulses in a nanodispersed birefringent medium is investigated. The matrix of the medium and chaotically mixed nanogranules form an amorphous photon crystal containing asymmetric molecules of identical chemical composition. The concentrations of molecules in the nanogranules and in the matrix are different. This nanodispersed (discrete) structure of the medium leads to spatial dispersion. The wave equation for the ordinary component of pulses propagating in such a medium is derived under the conditions of the sudden perturbation approximation. This equation generalizes the sine-Gordon and Rabelo–Fokas equations and appears to be integrable in the frameworks of the inverse scattering transformation method if an additional restriction on the parameters characterizing the spatial dispersion and anisotropy of the medium is imposed. This restriction implies that the medium is prepared in the quasiequilibrium state before the pulse effect, when the molecules in the matrix or the ones in the nanogranules are in the excited state. The soliton and breather solutions of the integrable wave equation are investigated.