Ultra-simplified design and quantitative analysis for the optical system of compact laser-induced breakdown spectroscopy

Abstract Optimization and simplification of optical systems represent a milestone in advancing the development of handheld and portable laser-induced breakdown spectroscopy (LIBS) systems towards smaller, more integrated forms. This research, for the first time, conducted a comprehensive optimization design and comparative analysis of three compact LIBS system Optical paths: the paraxial optical path (OP), the off-axis OP, and the reflective OP. The differences in spectral intensity and stability among these paths were revealed, providing a scientific basis for selecting the optimal OP for LIBS systems. The research found that the paraxial OP excels in spectral performance and quantitative analysis accuracy, making it the preferred choice for compact LIBS systems. Specifically, the paraxial OP significantly enhances spectral intensity, achieving a 6 times improvement over the off-axis OP and an even more remarkable 150 times increase compared to the reflective OP, greatly enhancing detection sensitivity. Additionally, the relative standard deviation, spectral stability index, maintains a consistently low level, ranging from 10.9% to 13.4%, significantly outperforming the other two OPs and ensuring the reliability of analytical results. In the field of quantitative analysis, the paraxial OP also demonstrates higher accuracy, precision, and sensitivity, comparing to other OPs. The quantitative analysis models for Si, Cu, and Ti elements exhibit excellent fitting, providing users with high-quality quantitative analysis results that are of great significance for applications in material science, environmental monitoring, industrial inspection, and other fields. In summary, this study not only confirms the enormous application potential of the paraxial OP in compact LIBS systems but also provides valuable practical experience and theoretical support for the miniaturization and integration of LIBS systems. Looking ahead, with continuous technological advancements, the design of the paraxial OP is expected to further propel the widespread adoption of LIBS technology in portable, on-site detection applications.