激光感生击穿光谱技术(LIBS)的原理及影响因素

激光感生击穿光谱技术（LIBS）具有不需制备样品，快速分析，可进行实时控制的特点显示了巨大实际应用价值，文中介绍了激光感生击穿光谱技术（LIBS）的发展历史、研究现状及其原理。同时通过重复频率为20 Hz，最高单脉冲能量为50　mJ的纳秒激光（10 ns，1　064 nm）研究了在不同激发条件下Cr和Co薄膜产生的光谱信号。得出对于Cr膜当激发能量小于10 mJ时，信号差异不明显。但是当激发能量超过10　mJ时将产生明显的变化。分析了激光特性、延迟时间、实验装置、环境气体的种类及压力、单/双脉冲、以及采用的理论分析方法对LIBS探测结果的影响。

The Theory and the Influential Factors of Laser Induced Breakdown Spectroscopy

The laser-induced breakdown spectroscopy (LIBS) technique, due to its lack of pretreatment of the material and the speed of analysis, has shown a great potential for a wide range of industrial applications. The current situation of application and study of LIBS are reviewed. Meanwhile, the laser used to explode the Cr and Co film had a pulse duration of 10 ns, the highest single pulse energy was 50 mJ at a repetition rate of 20 Hz, and a wavelength of 1 064 nm. When the excitation energy was less than 10 mJ, there was little difference in spectral signal excited by different energy for Cr film. Otherwise, the signal showed obvious change when excitation energy was higher than 10 mJ. The principle, characters, history and recent trend of LIBS were introduced systematically. The factors influencing LIBS performances, including the characteristic of laser, delay time, experiment setting, the kind and the pressure of surrounding. Gas, single or dual pulse, and the analysis method were analyzed.