Small Grants for Exploratory Research: Femtosecond Pulsed Laser Machining of Chemical Vapor Deposition (CVD)-Diamond

小行星9504102 研究了飞秒脉冲准分子激光精密加工化学气相沉积（CVD）金刚石薄膜的可行性。 预计金刚石的飞秒脉冲激光烧蚀与目前实践的纳秒或更长脉冲激光烧蚀显著不同，因为其能够提供极端强度和更大的吸收深度/热扩散距离比。 飞秒激光可以提供一种全新的激光-金刚石相互作用光谱，可以改变烧蚀产物的动力学（能量和质量分布），粒子发射的性质（电离，中性等）。 以及相关的现象，即等离子体形成和冲击传播。 因此，将有更大程度的待去除材料的雾化，减少烧蚀的热分量，在加工表面上不存在簇和微粒，以及金刚石转化为石墨的可能性更小。 这样的效果最终导致所提出的加工技术是一个高精度，无污染，时间效率高的程序崎岖的CVD金刚石膜，需要低的整体温度在加工过程中。 预计这种新型的激光加工方案不仅将完善现有的激光加工技术，而且还将超越所有其他金刚石微加工技术，此外，还将在其他研究领域（如薄膜沉积）产生新的应用。

9504102 Molian The feasibility of a novel femtosecond pulsed excimer laser processing technique for precision machining of chemical vapor deposition (CVD)-diamond films will be investigated. Femtosecond pulsed laser ablation of diamond is expected to be significantly different from that of currently practiced nanosecond or longer-pulsed laser ablation because of its capability to provide extreme intensities and larger absorption depth/thermal diffusion distance ratios. Femtosecond lasers can offer an entirely new spectrum of laser-diamond interactions that can alter dynamics of ablation products (energy and mass distribution), nature of particle emission (ionized, neutral, etc.) and associated phenomena namely plasma formation and shock propagation. Consequently, there will be a greater degree of atomization of material to be removed, reduced thermal component of ablation, absence of clusters and particulates on the machined surfaced, and less probability for the transformation of diamond to graphite. Such effects ultimately lead the proposed machining technique to be a high precision, contamination-free, time efficient procedure for craggy CVD-diamond films that requires low bulk temperature during machining. It is anticipated that this novel laser processing scheme will not only refine the existing laser-processing techniques but also surpass all other diamond micromachining techniques and, additionally, generate new applications in other areas of research such as deposition of thin films.