AI 中文总结
本研究结合泵浦-探测反射法与相位灵敏干涉泵浦-探测法，利用传输矩阵模型分析，实现了对金、铝、钢块体中散裂层的超快追踪，为GHz脉冲串加工的能量耦合研究提供关键参数。
AI 中文摘要
采用超短脉冲（USP）激光的极端制造需在皮秒至纳秒尺度理解烧蚀动力学，泵浦-探测反射法（PPR）可通过牛顿环（NR）干涉直接获取光机械散裂信息，但当散裂层光学不透明或烧蚀材料强烈衰减探测光时该特征会消失。本研究将PPR与相位灵敏干涉泵浦-探测法（PPI）结合，追踪钢、铝、金块体中的散裂层，即使反射探测信号被抑制95%以上，PPI仍可分辨传播中的散裂层。结合传输矩阵模型（TMM）的PPR/PPI联合分析可得到散裂层厚度、蒸汽层吸收及层分解时间，这些量是GHz脉冲串加工中后续脉冲能量耦合的关键决定因素。
英文摘要
Extreme manufacturing with ultrashort-pulse (USP) lasers at the physical limit of precision and efficiency requires understanding ablation dynamics on the picosecond-to-nanosecond timescale. Pump-probe reflectometry (PPR) provides direct access to photomechanical spallation through Newton ring (NR) interference, but this signature vanishes when the spallation layer becomes optically opaque or the ablated material strongly attenuates the probe. Here, we combine PPR with phase-sensitive interferometric pump-probe (PPI) measurements to track the spallation layer in bulk steel, aluminum, and gold. PPI resolves the propagating layer even when the reflected probe signal is suppressed by >95%. Joint PPR/PPI analysis with transfer-matrix modelling (TMM) yields spallation layer thickness, vapor layer absorption, and the layer disintegration times. These quantities are key determinants of the energy coupling of subsequent pulses in GHz burst processing.
