Producing an Efficient, Collimated and Thin Annular Beam with a Binary Axicon

TL;DR

This paper introduces a simple optical setup using a binary axicon and a lens to generate a thin, highly collimated annular beam with high efficiency, suitable for high-power laser applications.

Contribution

The authors demonstrate a novel method to produce a stable, efficient, and well-defined annular beam using a binary phase grating and lens, closely matching numerical simulations.

Findings

High conversion efficiency of annular beam production

Excellent agreement between measured and simulated beam profiles

Robust configuration suitable for high-power laser systems

Abstract

We propose and demonstrate a method to produce a thin and highly collimated annular beam that propagates similarly to an ideal thin Gaussian ring beam, maintaining its excellent propagation properties. Our optical configuration is composed of a binary axicon - a circular binary phase grating, and a lens, making it robust and well suited for high-power lasers. It has a near-perfect circular profile with a dark center, and its large radius to waist ratio is achieved with high conversion efficiency. The measured profile and propagation are in excellent agreement with a numerical Fourier simulation we perform.