正交双波长双脉冲LA-LIBS技术及其在原位元素显微分析中的应用

项目名称： 正交双波长双脉冲LA-LIBS技术及其在原位元素显微分析中的应用

项目编号： No.11304100

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 数理科学和化学

项目作者： 陈钰琦

作者单位： 华南理工大学

项目金额： 27万元

中文摘要： 为了从根本上解决激光诱导击穿光谱技术中空间分辨本领与灵敏度之间的矛盾，本项目提出了正交双波长双脉冲LA-LIBS的研究思想。用高质量大数值孔径显微物镜聚焦532nm或者266nm激光来剥离待分析样品，提高空间分辨本领；同时采用1064nm的近红外激光从垂直方向来二次激发被剥离的样品以提高光谱分析的灵敏度，实现对样品的高空间分辨高灵敏的原位元素显微分析。研究采用大芯径石英玻璃光纤传输1064nm激光脉冲并实现250ns以内的延时；精确测定样品的剥离阈值；在理想的聚焦和近阈值的剥离条件下，获得亚微米尺度的空间分辨本领。并利用所建立的技术开展贵金属合金等固体样品元素的原位显微分析，常见金属元素的检出限达到50ppm的水平。其技术成果可以弥补扫描电镜和激光剥离-电感耦合等离子体-质谱/原子发射光谱等分析技术的不足，在材料科学、生命科学、微电子、文物鉴定等领域具有较大的应用价值。

中文关键词： 激光剥离；二次激发；激光诱导击穿光谱；原位分析；

英文摘要： To solve the problem of the contradiction between spatial resolution and analysis sensitivity exists in single pulse laser-induced breakdown spectroscopy, the orthogonal dual-wavelength dual-pulse laser-ablation laser-induced breakdown spectroscopy (LA-LIBS) technique is proposed in this project. Where 532nm or 266nm laser pulse is focused by high quality objective with large numerical aperture to improve spatial resolution, and 1064nm laser pulse is used to excite the ablated sample from the direction which is perpendicular to the propagation direction of ablation laser beam to enhance analysis sensitivity. Thus in-situ microscopic analysis of elements with both high spatial resolution and high sensitivity can be realized. The tasks of this project include: (1) to transfer 1064nm laser pulse by quartz fiber with large core diameter and to realize time delay of less than 250ns. (2) to determine ablation threshold of the ablated samples with LA-LIBS accurately. (3) to achieve submicron spatial resolution under ideal focusing and near-threshold laser-ablation conditions;(4) to realize in-situ high spatial resolution elements microscopic analysis for some solid samples, such as alloys contain high priced metals. The limits of detection of common metal elements can be reached to 50ppm. This technique is helpful for

英文关键词： laser ablation；second excitation；LIBS；in-situ analysis；