Time-resolved techniques as probes for the laser ablation process
Time-resolved techniques as probes for the laser ablation process
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DOI：
10.1016/j.optlaseng.2004.03.013
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发表时间：
2005-03-01
影响因子：
4.6
通讯作者：
Wokaun, A
中科院分区：
文献类型：
--
作者：
Hauer, M;Funk, DJ;Wokaun, A
激光材料加工是一个日益增长的市场，尽管许多工艺仍未完全了解。人们一再强调，更好地了解瞬态过程有助于提高对烧蚀机理的理解。使用纳米表面干涉测量，纳米阴影成像和发射光谱的例子展示了如何使用这些技术在激光烧蚀过程中获得新的见解。时间分辨表面干涉法探测剩余的聚合物，而n -阴影法和等离子体光谱法观察烧蚀产物。n -阴影成像可用于刚好高于烧蚀阈值的影响，到等离子体被观察到的影响，这是由发射光谱探测的。对一种特殊设计的三氮烯聚合物进行了时间分辨纳米干涉测量，结果表明三氮烯聚合物的表面形貌发生了变化，因此表面去除仅在激光脉冲期间发生。利用n -阴影成像技术对激光烧蚀过程中产生的冲击波和碎片羽流进行了观测。对含能聚合物在1064 nm和193 nm两种不同波长下的烧蚀特性进行了比较，结果表明，只有在1064 nm照射后才会检测到非气态碎片（固体或液体）的喷射。在较高的激光影响下，等离子体形成，原子(H)和双原子物种（CN， CH和C-2）被识别。(c) 2004 Elsevier Ltd.版权所有。
Laser material processing is an increasing market although many processes are still not yet fully understood. It was repeatedly emphasized that a better understanding of the transient processes can help to improve the understanding of the ablation mechanism. Examples using ns-surface interferometry, ns-shadowgraphy and emission spectroscopy are shown to illustrate how these techniques can be used to obtain new insights in the laser ablation processes. Time-resolved surface interferometry probes the remaining polymer, while ns-shadowgraphy and plasma spectroscopy observe the ablation products. Ns-shadowgraphy can be used for fluences just above the ablation threshold, to the fluences where a plasma is observed, which is probed by emission spectroscopy. Time-resolved ns-surface interferometry of a specially designed triazene polymer reveals that the surface morphology changes and thereby the surface removal occurs only during the laser pulse. Ns-shadowgraphy is used to observe the shockwave and the plume of fragments, which are generated during laser ablation. A comparison of the ablation properties of an energetic polymer at two different wavelengths (1064 and 193 nm) shows that the ejection of non-gaseous fragments (solid or liquid) is only detected after irradiation with 1064 nm. At higher laser fluences, plasma is formed, and the atomic (H), and diatomic species (CN, CH and C-2) are identified. (c) 2004 Elsevier Ltd. All rights reserved.