基于空间外差光谱技术的LIBS系统高光谱分辨、高通量检测技术研究

Laser-induced breakdown spectroscopy (LIBS) is kind of rapid development spectral analysis technique. In the process of LIBS application, the characteristic emission lines of sample are numerous. There are always numerous characteristic emission lines in LIBS spectrum, and spectral overlapping and mutual interference of adjacent character lines are common problems because of the limit of instrument spectral resolution. Meanwhile, spectral resolution of traditional spectrometer used for the study of LIBS is limited by the width of entrance slit, which means that high spectral resolution and high optical throughput are inter-constraint. This phenomenon seriously affects the signal-noise ratio of spectrum and the accuracy of spectral analysis. Spatial heterodyne spectroscopy (SHS), which is based on Fourier transform spectroscopy of Fizeau interference fringes and the spectral resolution is not limited by slit, has advantages of ultra-high spectral resolution, high throughout, wavelength band optional and compact structure. This project will focus on the research of detection techniques of LIBS system based on the spatial heterodyne spectroscopy, to solve the contradiction between high spectral resolution and high throughput of traditional spectrum instrument. LIBS-SHS spectrum detection system and data processing method will be established. This research will provide a detection method for LIBS system with high spectral resolution and high throughput, and obtain high SNR LIBS spectra with character lines separated, which can be a powerful guarantee to improve the accuracy of LIBS technique for quantitative or qualitative analysis.

激光诱导击穿光谱技术（LIBS）是一项正在快速发展的光谱分析技术。在合金LIBS检测光谱中存在大量的特征发射谱线，而受限于光谱仪器分辨率，谱线重叠及相邻谱线互相干扰问题普遍存在。当前使用光谱仪器通常采用限制狭缝宽度来保证光谱分辨率，而这也降低了光谱仪所能获得的光通量。这一现状严重影响了LIBS光谱信噪比及光谱分析准确性。空间外差光谱技术（SHS）是基于Fizeau干涉条纹傅里叶变换光谱的一种新型超光谱分辨技术，光谱分辨率不受狭缝尺寸影响，具有超高光谱分辨、高光通量、波段可选、结构紧凑等优势。本课题将开展基于SHS技术的LIBS系统光谱探测技术研究，突破传统光谱仪器无法同时获得高光谱分辨率和高通量的限制，建立LIBS-SHS光谱检测系统及数据处理方法，实现高光谱分辨、高通量探测，进而获得信噪比良好、特征谱线分离的LIBS光谱信号，为提升LIBS技术定量、定性分析的准确性提供有力保障。

激光诱导击穿光谱技术（LIBS）是一项正在快速发展的光谱分析技术。在合金LIBS检测光谱中存在大量的特征发射谱线，受限于光谱仪器分辨率，谱线重叠及相邻谱线互相干扰问题普遍存在。对于通常使用的衍射型光谱仪，通常通过提高光栅线密度、减小入射狭缝宽度或采用更大尺寸的光学系统来获得更高分辨率，这又会导致光谱仪收光效率严重减低、大尺寸光学系统便携性差以及成本高等问题。为了解决传统衍射型光谱仪无法同时获得高光谱分辨率和高通量的矛盾，本项目开展基于空间外差光谱技术（SHS）的LIBS系统光谱探测技术研究，搭建了一套LIBS-SHS光谱检测实验系统，并发展了专门的数据处理方法。基于该系统，开展相关LIBS应用试验，获得了信噪比良好、特征谱线分离的LIBS光谱信号。