Isotropic and anisotropic spiraling photorefractive solitons

Summary form only given. The interaction of photorefractive (PR) solitons has attracted considerable research interest in recent years. Screening solitons emerge when laser beams of appropriate wavelength, intensity, and shape are launched into a PR crystal and a dc electric field is applied across, to induce self-focusing of beams through PR screening. The material response is an inherently anisotropic and nonlocal function of the propagating light intensity. The interaction between solitons is anomalous, in that they experience both attraction and repulsion. This feature prevents stable spiraling, and the beams oscillate about each other and eventually fuse. There is a different approach, which asserts that the PR screening process can be represented by isotropic models. Here the refractive index is locally modified and under proper initial conditions two solitons start to spiral about each other. We integrate both models for exactly the same initial and boundary conditions, and display how the differences evolve.