Probing the topological charge of a vortex beam with dynamic angular double slits

TL;DR

This paper presents an experimental method using dynamic angular double slits to accurately determine both the magnitude and sign of a vortex beam's topological charge by analyzing interference pattern variations.

Contribution

The study introduces a novel, efficient technique employing dynamic angular double slits to probe the topological charge of vortex beams, including its sign.

Findings

Successfully determined the topological charge modulus and sign.

Demonstrated precise and efficient measurement method.

Validated the approach through experimental results.

Abstract

When a vortex beam with the spiral phase structure passes through a dynamic angular double slits (ADS), the interference pattern changes alternatively between destructive and constructive at the angular bisector direction of the ADS due to their phase difference. Based on this property, we experimentally demonstrate a simple method, which can precisely and efficiently determine the topological charge of vortex beams. What is more, this scheme allows determining both the modulus and sign of the topological charge of vortex beams simultaneously.