Generation of optical vorticity from topological defects

TL;DR

This paper demonstrates that topological defects in a medium can generate optical vortices with quantized angular momentum, enabling new applications like liquid-crystal-based optical tweezers.

Contribution

It introduces a formalism linking torsion from topological defects to the generation of optical vortices with well-defined angular momentum.

Findings

Torsion causes quantized optical modes.

Generated modes possess well-defined orbital angular momentum.

Potential for designing liquid-crystal optical tweezers.

Abstract

The propagation of an electromagnetic wave in a medium with a screw dislocation is studied. Adopting the formalism of differential forms, it is shown that torsion is responsible for quantized modes. Moreover, it is demonstrated that the modes thus obtained have well defined orbital angular momentum, opening the possibility to design liquid-crystal-based optical tweezers.