阐述了激光诱导击穿光谱技术的基本原理,分析了金属材料表面光学性质与激光诱导等离子体辐射强度的关系,建立了空气中进行等离子辐射研究的试验装置,测量了不同厚度碳层下激光等离子体的发射光谱强度。实验结果表明：当一束近红外高能量脉冲激光(能量为5 J)作用于覆盖有约18 μm厚度碳层的标钢样品时,激光等离子体的发射光谱强度提高了16%～22%；证明了金属样品表面覆盖碳层能够提高激光等离子体辐射强度。

The working principle of the laser-induced breakdown spectroscopy(LIBS) was interpreted, and how the surface optical properties of metallic materials affects the laser-induced plasma radiation intensity was analyzed. An LIBS experimental system in the air was set up and the laser plasma emission spectrum intensity of carbon coatings with different thickness measured. The results show that the spectral line intensity of the laser-induced plasma increases by 16% to 22% when a bunch of high-energy laser (5 J) acts on the steel sample with a 8 μm thick carbon coating. It proves to be feasible that the laser-induced plasma radiation intensity can be increased by coating a carbon layer on the surface of the steel sample.