Determining the fractional topological charge shifting in perfect vortices from laser speckle

Abstract

We demonstrate analytically, numerically, and experimentally that the fractional topological charge shifting in perfect vortices having a ring-shaped distribution is precisely determined by the correlation coefficient of speckle distributions obtained by the scattering of these perfect vortices through a random phase screen. The scattering of elliptic perfect optical vortices is also analyzed and discussed.