Symmetry breaking of optical vortices: Birth and annihilation of singularities in the evanescent field

TL;DR

This paper demonstrates how optical vortices can be created, manipulated, and annihilated in evanescent fields near a material interface using total internal reflection and wave superposition, revealing new topological phenomena.

Contribution

It introduces a novel method to generate and control optical vortices in evanescent fields, extending vortex dynamics studies from free space to near-field optics.

Findings

Birth and annihilation of optical vortices observed in evanescent fields.

Topological features of vortices can be tuned by incident angles and amplitudes.

Potential for new curved optical vortex manipulation techniques.

Abstract

The interaction of optical vortices (or phase singularities, screw dislocations) with ordinary matter is treated with simple approach. Using total internal reflection phenomenon and superposition of four plane waves incident on a material with refractive index lower than the original propagating medium, we are able to show birth and annihilation of optical vortices in the evanescent field with curved topological features. Until now, this phenomenon has been explored only in free space propagation. By a suitable tuning process, involving the incident angles and the amplitudes of the incident plane waves, it is possible to create unusual topological features of optical vortices in the vicinity of the material. We believe that this work can open new aspects of curved optical vortex manipulation in near-field optics.