Verifica sperimentale delle prestazioni di una Spiral Phase Plate

Optical vortex (OV) are singularity of phase of a wavefront that takes a helical shape in the axis of propagation. A device called Spiral Phase Plate that, thanks to its shape can give the right phase shift for the generation of an OV. Along the optical axis of the vortex the phase singularity creates destructive interference: at the center there is a zone of shadow with a ring of light around it. This feature can be exploited for the direct observation of extrasolar planets.