The transverse shift of a high order paraxial vortex-beam induced by a homogeneous anisotropic medium

TL;DR

This paper investigates how a high-order paraxial vortex beam propagates through a uniaxial anisotropic medium, revealing vortex splitting, complex vortex interactions, and a transverse beam shift caused by vortex displacement.

Contribution

It demonstrates the vortex splitting and displacement phenomena in a uniaxial medium, providing new insights into vortex-beam behavior in anisotropic materials.

Findings

Vortex splitting into ordinary and extraordinary beams.

Vortices gather at the beam axis after dislocation reactions.

A vortex is displaced transversely, causing a beam shift.

Abstract

We consider the propagation of a tilted high order paraxial vortex-beam through a homogeneous anisotropic medium of a uniaxial crystal. We found that the initially circularly polarized beam bearing the l-order optical vortex splits into ordinary and extraordinary beams with a complex vortex structure. After a series of dislocation reactions the vortices gather together at the axis of the partial beam with the initial circular polarization shaping the l-order optical vortex. However, only l-1 vortices gather together on the axis of the partial beam with the orthogonal circular polarization. One optical vortex is shifted along the direction perpendicular to the inclination plane of the beam. Such a vortex displacement induces the transverse shift of the partial beam. In fact, we deal with the beam quadrefringence in a uniaxial, homogeneous anisotropic medium. The first two beams is a result of the splitting of the initial tilted beam into the ordinary and extraordinary once.