Characterizing the temporal rotation and radial twist of the interference pattern of vortex beam

TL;DR

This paper experimentally and theoretically investigates how the interference pattern of vortex beams exhibits temporal rotation and radial twist, influenced by physical parameters, with potential applications in pattern analysis and matter manipulation.

Contribution

It introduces a systematic method to quantify and control the temporal rotation and radial twist of vortex beam interference patterns using a Mach-Zehnder interferometer.

Findings

Good agreement between theory and experiment.

Identified parameters affecting rotation and twist.

Demonstrated control over interference pattern structures.

Abstract

We experimentally and theoretically characterize the temporal rotation and radial twist of the interference pattern of vortex beam with its conjugate copy. To quantitatively study the temporal rotation and radial twist, we controllably modify the conjugate beam with a frequency or wavefront curvature difference using a movable Mach-Zehnder interferometer. The effects of the physical parameters (i.e., the topological charge, frequency difference and wavefront curvature difference of the vortex beams) on the temporal rotation as well as radial twist are systematically explored. We further measure two parameters, the rotation velocity $\Omega$ and twist coefficient $\alpha$, respectively, to characterize the degree of the temporal rotation and radial twist of the interference pattern. The theory of the interference model on vortex beams have good agreements with the experimental results. This work is favorite to study the detailed structure of the interference pattern and manipulate matter with superimposed vortex beams.