Fine structure of “white” optical vortices in crystals

Representation of a perturbed optical vortex past a uniaxial crystal and a polarization filter on the complex plane and the orbital Poincaré sphere was experimentally and theoretically studied. It is shown that the main properties of a polychromatic optical vortex are adequately described using eight experimentally measured quantities, including four orbital and four spin Stokes parameters of a singular beam.