Detailed knowledge about the laser-material interaction, especially the distribution of laser power absorption, is a prerequisite for the simulation and optimization of laser material processing. In this work, an algorithm based on ray tracing is presented to calculate the propagation and the absorption of a laser beam inside a complex 3D cutting kerf. To model the laser beam precisely, a ray source based on high-power intensity measurements of the laser beam emitted from a highly multimode step-index fiber is set up. For the 3D reconstruction of the cutting kerf geometry, a semicircle model derived from three characteristic lines of so-called “frozen cuts” is applied. The presented approach enables a direct simulation of the laser absorption inside the cutting kerf considering light propagation properties like beam degeneration, shadowing effects, and multiple reflections. As a benchmark, it is finally applied to analyze cutting experiments in stainless steel with an axicon telescope.

中文翻译：

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在 3D 激光切割切口内吸收定制的激光束

关于激光-材料相互作用的详细知识，特别是激光功率吸收的分布，是模拟和优化激光材料加工的先决条件。在这项工作中，提出了一种基于光线追踪的算法来计算复杂 3D 切割切口内激光束的传播和吸收。为了精确地模拟激光束，建立了一个基于从高多模阶跃折射率光纤发射的激光束的高功率强度测量的射线源。对于切割切口几何形状的 3D 重建，应用了源自三个所谓“冻结切割”特征线的半圆模型。考虑到光束退化、阴影效应、和多次反射。作为基准，它最终被用于用轴棱镜望远镜分析不锈钢的切割实验。