中文摘要：

脉冲激光束在低真空（约2Pa）环境下聚焦到高纯Zn靶表面，烧蚀区域不仅有中心深孔的宏观损伤，而且还发现大量微米量级的类似足球形状的金属Zn球体结构附着生长在孔洞内侧表面．实验过程中采用等离子体光谱诊断技术研究宏观和微观损伤对后续脉冲激光的影响程度．与聚焦于金属Zn平滑表面相比，宏观损伤可以使后续激光诱导的Zn原子334．5nm谱线强度提高10．3％，在此基础上大量Zn微米球体附着在内表面可以使谱线强度再提高34．3％．因此，推断这些金属Zn微球表面镶嵌着光洁的纳米量级六边形和五边形小平面，可以对后续脉冲激光产生镜面反射，使得激光能量汇聚并耦合增强，提高烧蚀效率．实验结果还表明，这些微米球体的数目随着激光脉冲次数的增加而增多，使得后续激光能够诱导产生更为致密高温的等离子体．研究结果有望为激光．金属微孔技术提供新思路．

英文摘要：

Numerous football-shaped Zinc micro-spheres on inner surface of the crater are produced by pulsed laser ablation of Zn metals in vacuum condition （-2 Pa）. Pulsed laser induced plasma emission spectrum is measured to reveal the effects of macro and microstructures on subsequent pulse laser ablation. The intensity of spectral line at 334.5 nm originating from Zn atoms by subsequent laser ablation of the ablated spot is 10.3% higher than that created over a smooth surface. The intensity of the same spectral line produced over a ablated spot with a great number of micro-spheres is 1.343 times higher than that produced by the plasma generated over the ablated spot. The Zn micro-sphere completely covered with nano-scaled regular pentagonal and hexagonal facets can lead to an enhanced absorption of the following laser energy. The total number of Zn micro-spheres increases as the number of laser shots increses, which can result in hotter and dense plasma by subsequent laser ablation. The proposed results are of importance for developing the laser micro-drilling technique.