Electrically controlled liquid crystalic Frenel lens and determination of topological charge of optical vortices

Abstract

A new simple and effective interference method for determining the phase topology of optical vortices is proposed using a developed and manufactured microstructured twist-planar oriented nematic liquid crystal Fresnel zone plate. The developed method eliminates the need to use an additional reference wave and allows direct analysis of the vortex phase topology without an interferometer and without changing the optical scheme. The method was tested for operability in the spectral range from 532 nm to 1.1 µm using nanosecond laser pulse radiation. The efficiency of the developed method was confirmed both experimentally and theoretically.