超光学衍射限高空间分辨的双波长激光剥离-激光诱导击穿光谱元素显微分析

项目名称： 超光学衍射限高空间分辨的双波长激光剥离-激光诱导击穿光谱元素显微分析

项目编号： No.11274123

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 李润华

作者单位： 华南理工大学

项目金额： 93万元

中文摘要： 为了实现固体样品中微区元素的超光学衍射限高空间分辨显微分析,本项目拟开展基于一台纳秒Nd:YAG激光器的532-1064nm和266-1064nm两种波长组合的双波长激光剥离(LA)-激光诱导击穿光谱(LIBS)研究。采用大芯径石英光纤实现1064nm激光的延时；用LIBS准确测定不同样品的激光剥离阈值；采用时间分辨单光子计数技术提高光谱检测灵敏度；在理想的聚焦条件和近阈值的剥离条件下,获得超光学衍射限的高空间分辨本领；并利用所建立的技术开展生物样品和合金的高空间分辨元素显微分析。该项目可以系统地建立起双波长LA-LIBS技术,实现对样品中主要元素和微量元素的高空间分辨显微分析,空间分辨本领达到200nm甚至更高的水平。该项目不仅可以较好地解决LIBS研究中高空间分辨本领和高灵敏度之间的矛盾,具有较大的科学意义；其技术成果还可以在生物、医学、材料科学、微电子和纳米科学等领域获得广泛的应用。

中文关键词： 激光剥离；激光诱导击穿光谱；超衍射限；高空间分辨；元素显微分析

英文摘要： To realize super-diffraction-limited high spatial resolution microscopic analysis of the localized elements in solid samples, a dual-wavelength laser-ablation (LA) laser-induced breakdown spectroscopy (LIBS) technique will be studied based on one nanosecond Nd:YAG laser and with two wavelength combinations (These are 532-1064nm and 266-1064nm combinations.) The tasks of this project include: (1) to realize time delay of the 1064nm laser pulse by quartz fiber with large core diameter; (2) to determine laser-ablation thresholds accurately for different samples with LIBS; (3) to enhance spectroscopic detection sensitivity with time-resolved photon-counting technique; (4) to achieve super-diffraction-limited high spatial resolution under ideal focusing and near-threshold laser-ablation conditions; and (5) to realize high spatial resolution elements microscopic analysis to biological samples and alloys. The dual-wavelength LA-LIBS technique will be systematically established after thorough studies in this project. A super-diffraction-limited high spatial resolution microscopic analysis of both major and minor elements in samples can be realized, and the spatial resolution can be reached to 200 nm and even less than 200 nm. This project can not only solve the problem of the contradiction between high spatial resolutio

英文关键词： laser-ablation；laser-induced breakdown spectroscopy；surpass diffraction limit；high spatial resolution；element microscopic analysis