Polarization pattern of vector vortex beams generated by $q$-plates with different topological charges

TL;DR

This study investigates the polarization topologies of vector vortex beams generated by $q$-plates with various topological charges, demonstrating control over radial and azimuthal polarizations through input polarization adjustments.

Contribution

It provides experimental analysis of polarization structures for different $q$-plates and introduces dynamic switching between polarization states using a $q=1/2$-plate.

Findings

Polarization patterns depend on $q$-plate charge and input polarization.

Dynamic switching between radial and azimuthal polarizations is achieved.

Experimental mapping of Stokes parameters reveals detailed polarization topologies.

Abstract

We describe the polarization topology of the vector beams emerging from a patterned birefringent liquid crystal plate with a topological charge $q$ at its center ($q$-plate). The polarization topological structures for different $q$-plates and different input polarization states have been studied experimentally by measuring the Stokes parameters point-by-point in the beam transverse plane. Furthermore, we used a tuned $q=1/2$-plate to generate cylindrical vector beams with radial or azimuthal polarizations, with the possibility of switching dynamically between these two cases by simply changing the linear polarization of the input beam.