Generalized and multiplexed $q$-plates: experimental implementation

TL;DR

This paper generalizes $q$-plates to create complex polarization and phase structures in light beams, demonstrating an experimental implementation with liquid crystal devices and multiplexing capabilities for advanced beam shaping.

Contribution

It introduces a generalized $q$-plate concept with arbitrary functions, and develops an LCoS-based device for experimental realization and multiplexed superpositions of vector and vortex beams.

Findings

Theoretical and experimental results show great agreement.

Generalized $q$-plates enable complex polarization and phase control.

Multiplexed $q$-plates allow arbitrary superpositions of beams.

Abstract

In this paper we generalize the concept of $q$-plate, allowing arbitrary functions of both the radial and the azimuthal variables, and study their effect on uniformly polarized beams in the near and far-field regime. This gives a tool for achieving beams with hybrid states of polarization (SoPs), and alternative phase and intensity distributions. We also implement an experimental device based on a liquid crystal on silicon (LCoS) display for emulating these generalized $q$-plates. Moreover, we propose an application that takes advantage of the pixelated nature of this kind of devices for creating arbitrary superpositions of vector and vortex beams by representing onto the LCoS randomized combinations of two different $q$-plates, i.e. multiplexed $q$-plates. Great agreement is found between theoretical and experimental results.