Universal Snell’s law & bright spatial soliton refraction

The behaviour of a scalar optical beam at the boundary between two dissimilar Kerr media is of fundamental interest in nonlinear photonics. Since this class of problem is intrinsically nonparaxial, the limitations of conventional (paraxial) theory must be observed with care. Recently, we proposed the first Helmholtz model of Kerr spatial soliton refraction that is valid across the entire range of incidence, reflection and refraction angles. Here, we report the first systematic generalization of these novel analyses to a wider class of power-law materials. Soliton refraction laws will be given, and excellent agreement shown between theoretical predictions and computer simulations. New qualitative phenomena are also uncovered in non-Kerr regimes