激光诱导击穿光谱是一种前沿性光谱分析技术，可广泛应用于石油、冶金和电力等领域的现场在线检测。但是当LIBS技术用于微量元素检测时，由于光谱信号强度较弱，导致其分析精度较低、检出限偏高。现有LIBS信号增强方法，在实现过程中需要额外增加激发源，导致仪器结构复杂、成本较高，不利于现场在线检测。本项目针对这一问题，建立等离子体吸收区理论模型，揭示等离子体屏蔽效应的内在机理，通过改善系统内部激光能量的利用效率，提出一种基于单光束分束激发的LIBS信号增强方法(SBS-LIBS)。研究本项目方法对不同光谱波段和元素种类的响应效果，优化实验条件，建立完善的分析测试体系，探索方法对于信号增强的深层机理。本项目提出的方法谱峰强度增加5~8倍，信噪比增加2~4倍，同时还保留了原有LIBS技术的优势，有效解决现有LIBS信号增强方法仪器结构复杂，分析时效性较差等问题，为其服务于现场在线检测奠定重要的技术基础。

Laser-induced breakdown spectroscopy is a frontier spectra analysis technique in online testing involved in soil, metallurgy and other fields. The LIBS signal is relatively weak in trace elements detection which leads to low accuracy and high LOD. The existing signal enhancement methods need extra excitation source, and these methods will make the instrument complicated and expensive. According to this problem, we will establish theoretical model of plasma absorption zone to reveal the inherent mechanism of plasma shielding effect. By improving the use efficiency of the laser energy within the system, a signal enhancement method based on single-beam splitting(SBS-LIBS) excitation is proposed. In addition, the response of different spectral bands and types of elements will be researched to optimize testing condition and establish a comprehensive analysis and testing system. This method with the inherent advantage of LIBS has a relative simple structure and can solve the problem of poor timeless for tradition method. It achieves 5-8 times enhancement in peak intensity and 2-4 times enhancement in S/N. The method proposed in this project will be technical basis for online testing.