Design, development and evaluation of a laser-induced optical emission spectrometer for remote characterization of solid samples.

Abstract

Laser-Induced Breakdown Spectroscopy (LIBS) is a versatile technique for rapid and nondestructive elemental analysis of solid materials. Its ability to operate under stand-off conditions makes it highly attractive for applications involving hazardous, moving, or inaccessible samples. However, optimizing LIBS instrumentation for remote characterization remains challenging, particularly regarding laser–plasma interaction, light collection efficiency, and spectral quality. This Master’s Thesis presents the design, development, and evaluation of two LIBS system configurations. The setups differed mainly in the laser source employed, while the optical collection system remained identical. This strategy was intended to address the analysis of both fixed and moving samples and to provide practical insight into the design and assessment of stand-off LIBS instrumentation. The spectrometer components—including laser source, beam delivery optics, fiber-bundle light collection, spectrometer, and detector—were integrated and tested. The developed system was applied to galvanized steel (Zn/Fe) samples to demonstrate depth profiling and interfacial detection capabilities. Additionally, a comparative study between two optical collection configurations (2-fiber and 19-fiber bundles) was performed to evaluate signal intensity, stability, and reproducibility under stand-off conditions. The results confirm that both system configurations enable reliable elemental analysis, with clear identification of interfacial layers and consistent signal acquisition. These findings highlight the potential of the proposed LIBS setups as flexible tools for industrial and scientific applications requiring remote characterization of solid samples.