Effect of laser beam shaping on the determination of manganese and chromium elements in steel samples using laser-induced breakdown spectroscopy

摘要

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 (R-2) 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.