Zhou Qi, Chen Yuqi, Peng Feifei, Yang Xuejiao, Li Runhua
Department of Physics, School of Science, South China University of Technology, Guangzhou, China.
Appl Opt. 2013 Aug 10;52(23):5600-5. doi: 10.1364/AO.52.005600.
Orthogonal dual-pulse laser-ablation laser-induced breakdown spectroscopy was first used to determine the laser-ablation threshold of samples. In this technique, the first laser pulse was used to ablate samples and the second time-delayed laser pulse was used to break down the ablated samples. Orthogonal geometric arrangement was adopted in this technique to ensure both high spatial resolution and high detection sensitivity. By monitoring the intensities of the atomic emission of the plasma under different pulse energies of the ablation laser and using an extrapolation method, the minimum pulse energy needed for the ablation of copper alloy under the tightly focused condition with a nanosecond 532 nm ablation laser was determined to be 1.9±0.1 μJ. After experimentally determining the beam spot size on the focal plan, the fluence threshold of the studied sample was determined to be 0.64±0.06 J/cm². This technique is able to realize direct and sensitive determination of a laser-ablation threshold of solid samples, and it is possible to find some important applications in different fields.
正交双脉冲激光烧蚀激光诱导击穿光谱法首次用于测定样品的激光烧蚀阈值。在该技术中，第一个激光脉冲用于烧蚀样品，第二个延迟激光脉冲用于击穿烧蚀后的样品。该技术采用正交几何排列以确保高空间分辨率和高检测灵敏度。通过监测烧蚀激光不同脉冲能量下等离子体的原子发射强度并采用外推法，确定了在纳秒532nm烧蚀激光紧密聚焦条件下铜合金烧蚀所需的最小脉冲能量为1.9±0.1μJ。在通过实验确定焦平面上的光斑尺寸后，所研究样品的能量密度阈值确定为0.64±0.06J/cm²。该技术能够直接且灵敏地测定固体样品的激光烧蚀阈值，并且有可能在不同领域找到一些重要应用。
