等离子体光栅与光丝非线性耦合诱导击穿光谱

激光诱导击穿光谱技术（laser-induced breakdown spectroscopy，LIBS）是一种分析样品元素信息的有效工具，具有快速、简便、实时的优点，可以对固体、液体和气体中多元素成分进行定性分析和定量检测。但传统的LIBS以及光丝诱导击穿光谱技术（filament-induced breakdown spectroscopy，FIBS）受限于峰值功率钳制，灵敏度难以提高，导致在实际应用中具有一定的局限性，成为LIBS技术发明以来一直面临的重大技术瓶颈。本文从激发源的角度出发，讨论了LIBS和FIBS出现的问题，介绍了近年来优化LIBS技术的研究进展，将多光束耦合形成的等离子体光栅应用于LIBS，在保留其原有优点的基础上，有效克服了等离子体屏蔽效应、基体效应，突破了功率钳制，增强了谱线信号，提高了探测灵敏度和定量分析能力。这些研究将推进LIBS技术在各领域的实际应用，同时为飞秒激光等离子体与其他技术的结合提供了研究思路。

Breakdown spectroscopy induced by nonlinear coupling of filaments and plasma gratings

Laser-induced breakdown spectroscopy (LIBS) is an effective tool for element analysis, which has the advantages of being fast, simple and real-time. It can be used for qualitative analysis and quantitative detection of various elements in solids, liquids and gases. However, the traditional LIBS and filament-induced breakdown spectroscopy (FIBS) have intensity clamping and their sensitivity is difficult to improve, which leads to certain limitations in practical application. This has become a major technical bottleneck since the invention of LIBS technology. From the perspective of excitation sources, this paper discusses the problems of LIBS and FIBS, and introduces the research progress of optimizing LIBS in recent years. The plasma grating formed by multi-beam interference is applied to LIBS. On the basis of retaining its original advantages, the plasma shielding effect and matrix effect are effectively overcome, the intensity clamping is broken, the spectral line signal is enhanced, and the detection sensitivity and quantitative analysis ability are improved. These studies will promote the practical application of LIBS technology in various fields, and also provide research ideas for the combination of femtosecond laser plasma and other technologies.