固相同位素比值分析在多个学科中都有着重要应用。目前利用激光诱导击穿光谱（LIBS）进行固相同位素比值分析的关键问题是最小分辨率和测量精度都较差，难以满足实际应用要求。本项目提出利用共焦Fabry-Perot（F-P）腔技术来大幅提高LIBS的空间分辨率，其中腔镜镀宽带介质膜以增加可测元素种类；基于Knudsen-layer理论，结合实验参数，建立等离子体电离度判据，选择有效的荧光光谱；根据Kelly气体动态流模型建立等离子体中粒子速率的时空分布模型，以确定最佳的延时和采光位置，削弱Doppler加宽效应；利用多级干涉条纹及多元多阶非线性逆回归模型获得同位素比值的定标方程，提高测量精度。本项目方法和技术不仅为高分辨光谱分析提供一种新的探测手段，而且为低成本、多元素、高精度、高分辨型LIBS固相同位素比值分析系统的实现开辟一条新的途径。

Solid-phase isotope ratio analysis has important applications in multiple disciplines. The poor minimum resolution and measurement accuracy are currently the two key issues for solid-phase isotope ratio analysis using laser-induced breakdown spectroscopy (LIBS), which are unable to meet the requirements of practical application. This project intends to ultilize a confocal Fabry-Perot (FP) cavity, which is covered with a broadband dielectric film to increase the number of measurable elements, to significantly improve the spatial resolution; based on the Knudsen-layer theory, combined with the experimental parameters, try to build the plasma ionization degree criterion to select the effective fluorescence spectroscopy; according to the Kelly gas dynamic flow model to establish the rate of plasma particles in the temporal and spatial distribution model to determine the optimal delay time and optical collection positon, so as to weaken the Doppler broadening effect; to obtain the isotopic ratio calibration formula by using both multi-level fringes and multi-order non-linear inverse regression model, so as to improve the measurement accuracy. The methods and techniques of this project not only provides a new means of high-resolution spectroscopy for detection, but also open up a new way for design of a low-cost, multi-element, high-precision, and high-resolution LIBS-based solid phase isotope ratio analysis system.