Thermal lensing-induced bifocusing of spatial solitons in Kerr-type optical media

Thermo-optical effects cause a bifocusing of incoming beams in optical media, due to the birefringence created by a thermal lens that can resolve the incoming beams into two-component signals of different polarizations. We propose a nonperturbative theoretical description of the process of formation of double-pulse solitons in Kerr optical media with a thermally induced birefringence, based on solving simultaneously the heat equation and the propagation equation for a beam in a one-dimensional medium with uniform heat flux load. By means of a nonisospectral Inverse Scattering Transform assuming an initial solution with a pulse shape, a one-soliton solution to the wave equation is obtained that represents a double-pulse beam whose characteristic properties depend strongly on the profile of heat spatial distribution.