Abstract To investigate the effect of laser beam shaping on the determination of manganese (Mn) and chromium (Cr) elements in steel samples with different matrices using laser-induced breakdown spectroscopy (LIBS), a commercial beam shaper was used to convert the Gaussian laser into a top-hat laser. Owing to the uniform beam energy distribution and the less unwanted heating, the crater produced by the top-hat laser is much flatter and smoother than that produced by the Gaussian laser. The leave-one-out cross-validation (LOO-CV) method was used to evaluate the predictive capability of the calibration models. After laser beam shaping, the determination coefficient (R2) values of the calibration curves were slightly improved, and the root mean squared error of cross-validation (RMSECV), relative error (RE), relative standard deviation (RSD), and the limits of detection (LOD) values were all about 2 times reduction. The results indicate that the laser beam shaping method is an effective approach to reduce the matrix effect and improve the repeatability and accuracy of LIBS.

中文翻译：

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激光束整形对激光诱导击穿光谱法测定钢样品中锰和铬元素的影响

摘要 为了研究激光光束整形对使用激光诱导击穿光谱 (LIBS) 测定不同基质钢样品中锰 (Mn) 和铬 (Cr) 元素的影响，使用商用光束整形器将高斯激光转换为成顶帽激光。由于光束能量分布均匀且不需要的加热较少，因此顶帽激光产生的陨石坑比高斯激光产生的陨石坑更平坦、更光滑。留一法交叉验证（LOO-CV）方法用于评估校准模型的预测能力。激光光束整形后，校准曲线的决定系数（R2）值略有提高，交叉验证的均方根误差（RMSECV）、相对误差（RE）、相对标准偏差（RSD）、检测限（LOD）值均降低了约 2 倍。结果表明，激光束整形方法是降低基体效应、提高LIBS重复性和精度的有效途径。