Non-Diffractive 3D Polarisation Features of Optical Vortex Beams

TL;DR

This paper demonstrates that specific polarization features of optical vortex beams remain constant in size regardless of diffraction, which could impact high-resolution imaging and metrology.

Contribution

The study analytically and through simulations reveals diffraction-independent polarization features near phase singularities in optical vortex beams.

Findings

Polarization features are invariant to diffraction.

Features are linked to longitudinal electric fields.

Potential applications in metrology and imaging.

Abstract

Vector optical vortices exhibit complex polarisation patterns due to the interplay between spin and orbital angular momenta. Here we demonstrate, both analytically and with simulations, that certain polarisation features of optical vortex beams maintain constant transverse spatial dimensions independently of beam divergence due to diffraction. These polarisation features appear in the vicinity of the phase singularity and are associated with the presence of longitudinal electric fields. The predicted effect may prove important in metrology and high resolution imaging applications.