Polarization and topological charge conversion of exact optical vortex beams at normal incidence on planar dielectric interfaces

We report on the exact resolution of the problem of reflection and refraction of exact circularly polarized Bessel vortex beams impinging at normal incidence on a planar dielectric interface between two isotropic and lossless media. On the one hand, we demonstrate the generation of a new vortex state both in the reflected and refracted fields. On the other hand, we show the possibility to completely convert, at reflection, the incident vortex beam into a vortex beam with orthogonal polarization and topological charge changed by ±2. The spin-orbit interaction of light occurring at the planar interface is identified as the mechanism responsible for these effects