为了减小激光诱导等离子体发射光谱中光谱线的自吸收效应, 提高激光光谱分析技术对物质中高含量元素的检测水平, 实验采用了一种平面反射镜装置约束等离子体, 比较了有或无平面反射镜装置时光谱线的线型变化。实验表明, 在无平面反射镜装置时, 样品元素Al, Mg和Mn的光谱线半高全宽度分别为0.16, 0.24, 0.058 nm, 而采用由四块平面反射镜组成的装置在空间上约束激光等离子体时分别为0.11, 0.13, 0.047 nm。结果表明, 光谱线的自吸收明显减小, 谱线线型变得比较锐且强度显著提高。通过观测等离子体照片, 测量等离子体温度和电子密度, 分析讨论了激光光谱自吸收效应降低的原因。

In order to reduce the self-absorption effect of spectral lines in the laser induced plasma emission, which could improve the detection level of laser spectral analysis technology for high-content elements in materials, a plane mirror device was used to constraint plasma in the experiment. The change of the spectral lines with or without the plane mirror device was compared. Without the plane mirror device, the half-maximum line widths of spectral line of the sample element Al, Mg and Mn were 0.16 nm, 0.24 nm and 0.058 nm, respectively. But they were 0.11 nm, 0.13 nm and 0.047 nm with four plane mirrors device constraining plasma. It shows that the self-absorption effect of spectral lines decrease significantly by the use of plane mirror device to restrain plasma on the space, while the spectral line becomes sharper and the intensity is improved significantly. By observing the plasma photos and measuring of plasma temperature and electron density, the reason to reducing the self-absorption effect in laser spectrum is discussed.