发表机构
Carnegie Mellon University; University of Michigan; National Institute of Standards and Technology（卡内基梅隆大学; 密歇根大学; 国家标准与技术研究院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
针对汽化诱导空腔中多次反射增强激光吸收的问题，提出基于有效单次反射光学深度的降阶模型，分离几何与光学效应，实现高效吸收率预测与锁孔表征。
AI 中文摘要
多次内部反射增强了汽化诱导空腔中的激光吸收，但将光线历史、空腔几何形状和吸收率联系起来通常需要完整的射线追踪。我们开发了一个基于Beer-Lambert型衰减的降阶框架，该衰减由有效单次反射光学深度（EPROD）控制。一种功率加权公式在恒定有效单次相互作用吸收率下定义了吸收率等效相互作用次数，而累积量展开将EPROD无关的平均相互作用次数与射线路径异质性修正分开。在涵盖三种合金和三种光斑直径的九个模拟组中，平均相互作用次数遵循单位截距的线性深度关系，R平方值为0.7824-0.9843。在固定光斑直径下，其斜率在不同合金间仅变化3.4%-6.3%，并随光斑直径增大而减小。根据射线统计固定该斜率，得到一个具有一个拟合参数的吸收率-深度模型，其中位预测误差（MAPE）为2.61%。一项独立的同步Ti-64实验得到的模型参数与相应模拟值相差约2.4%。该框架将几何相互作用累积与光学衰减分离，实现了高效的能量耦合预测和基于吸收率的锁孔表征。
英文摘要
Multiple internal reflections enhance laser absorption in vaporization-induced cavities, but connecting ray histories, cavity geometry, and absorptance typically requires full ray tracing. We develop a reduced-order framework based on Beer-Lambert-type attenuation governed by an effective per-reflection optical depth (EPROD). A power-weighted formulation defines an absorptance-equivalent interaction count under constant effective single-interaction absorptance, while a cumulant expansion separates the EPROD-independent mean interaction count from ray-path heterogeneity corrections. Across nine simulation groups spanning three alloys and three spot diameters, the mean interaction count follows a unit-intercept linear depth relation with R-squared values of 0.7824-0.9843. Its slope varies by only 3.4%-6.3% across alloys at fixed spot diameter and decreases with increasing spot diameter. Fixing this slope from ray statistics yields an absorptance-depth model with one fitted parameter and a median prediction error (MAPE) of 2.61%. An independent synchronized Ti-64 experiment yields model parameters within approximately 2.4% of corresponding simulation values. This framework separates geometric interaction accumulation from optical attenuation, enabling efficient energy-coupling prediction and absorptance-based keyhole characterization.
Comments29 pages, 7 figures
