A flexible, fast and benchmarked vectorial model for focused laser beams

TL;DR

This paper introduces a high-precision measurement method and a fast, flexible software tool for analyzing the volumetric field distribution of focused laser beams, aiding in material processing applications.

Contribution

It presents a novel measurement technique and an in-house software for rapid, accurate vectorial analysis of laser focus fields, accounting for optical aberrations.

Findings

Measurements achieve 300-nm longitudinal and diffraction-limited lateral resolution.

Simulations closely match experimental propagation imaging data.

The model effectively evaluates energy deposition in in-bulk laser processing.

Abstract

In-bulk processing of materials by laser radiation has largely evolved over the last decades and still opensup new scientific and industrial potentials. The development of any in-bulk processing application relieson the knowledge of laser propagation and especially the volumetric field distribution near the focus.Many commercial programs can simulate this, but, in order to adapt them, or to develop new methods,one usually needs to create a specific software. Besides, most of the time people also need to measurethe actual field distribution near the focus to evaluate their assumptions in the simulation. To easily get access to this knowledge, we present our high-precision field distribution measuring method and release our in-house software InFocus, under the Creative Commons 4.0 License. Our measurementsprovide 300-nm longitudinal resolution and diffraction limited lateral resolution. The in-house softwareallows fast vectorial analysis of the focused volumetric field distribution in the bulk. The simulationsof light propagation under different conditions (focusing optics, wavelength, spatial shape, propagationmedium) are in excellent agreement with propagation imaging experiments. The aberrations provoked by the refractive index mismatch as well as those induced by the focusing optics are both taken into account.The results indicate that our proposed model is suitable for the precise evaluation of energy deposition