Recently, A research team led by ZHANG Zhirong with Anhui Institute of Optics Fine Mechanics under Hefei Institutes of Physical Science realized a new approach to improve beam shaping quality in laser-induced breakdown spectroscopy (LIBS).
Iron and steel are important materials, and the content and ratio of the trace metal elements such as manganese (Mn) and chromium (Cr) directly affect the quality and performance of them.
Traditional analysis methods can indeed achieve high sensitivity and accuracy. But due to their own factors, it is very hard to realize in-site production, real-time and fast analysis.
As for LIBS technology, it has attracted much attention with no need for sample pretreatment, multi-element analysis, remote in-situ analysis.
The research team working together with Tsinghua University on the effect of laser beam shape on the determination of Mn and Cr in different matrix steel samples by LIBS technology.
The joint team introduced focusing lens optical module group to shape the Gaussian laser beam into the flat-topped laser beam with uniform energy distribution.
Due to the uniform laser energy distribution, stable ablation, and with no need for heating, they obtained better flat-topped beam that was flatter, smoother, and more balanced than the Gaussian beam.
In addition, the team evaluated predictive ability of the calibration model by using leave-one-out cross-validation (LOO-CV). The results shew an dramatic improvement in determination coefficient of the calibration curve, root mean square error, relative error elative standard deviation and low detection limit.
Therefore, the flat-topped laser beam shaping method could provide an effective method to reduce the matrix effect and improve the measurement repeatability and accuracy, laying a good foundation for the practical application of LIBS.
The above research work was supported by the National Natural Science Foundation of China, the Knowledge Innovation Project of the Chinese Academy of Sciences and the State Key Laboratory Fund.
Link to the paper: Effect of laser beam shaping on the determination of manganese and chromium elements in steel samples using laser-induced breakdown spectroscopy