Detection of partially coherent polarization singular vector beams using Stokes polarimetry

Abstract

We have demonstrated, theoretically and experimentally, a method based on Stokes polarimetry to detect the polarization singularity index (PSI) and the state-of-polarization (SOP) distribution of a partially coherent polarization singular vector beam. It is observed that on reducing the spatial correlation in polarization singular vector beams, the information of the phase vortex and polarization vortex is lost, yielding identical intensity profiles tending toward Gaussian distribution. However, the residual correlated field that comprises the polarized part of irradiance distribution still preserves these vortex structures. The PSI of a partially coherent vector beam can be readily obtained from the flower patterned image of the Stokes parameter's distribution. A uniform deterioration in the magnitude of Stokes intensity all across the beam cross section is observed as a signature of reduced two-point correlation. The respective Stokes phase maps are also invariant and can be used to determine the SOP distribution. The present study foresees potential application in free-space optical communication, optical trapping, and imaging, where the coherence properties of the polarization singular vector beams are of considerable importance.