A fiber-based beam profiler for high-power laser beams in confined spaces and ultra-high vacuum

TL;DR

This paper introduces a fiber-based beam profiler capable of measuring high-power laser beams in ultra-high vacuum and confined spaces, offering a simple, compact, and reliable alternative to traditional systems.

Contribution

A novel fiber-based beam profiling method that functions effectively in ultra-high vacuum and confined spaces, with high resolution and laser intensity tolerance.

Findings

Comparable resolution to commercial systems

Operates through apertures smaller than 500x500 μm²

Withstands laser intensities over 2 MW/cm²

Abstract

Laser beam profilometry is an important scientific task with well-established solutions for beams propagating in air. It has, however, remained an open challenge to measure beam profiles of high-power lasers in ultra-high vacuum and in tightly confined spaces. Here we present a novel scheme that uses a single multi-mode fiber to scatter light and guide it to a detector. The method competes well with commercial systems in position resolution, can reach through apertures smaller than $500\times 500$~$\mu$m$^2$ and is compatible with ultra-high vacuum conditions. The scheme is simple, compact, reliable and can withstand laser intensities beyond 2~MW/cm$^2$.