Comparing LIBS of marine coatings using femtosecond pulses and continuous wave laser cleaning

This study investigates the laser removal process of marine protective coatings using laser-induced breakdown spectroscopy (LIBS). A high pulse repetition rate femtosecond laser system is first employed in a controlled laboratory setting to examine how different coating samples and laser parameters influence the LIBS signal. By systematically varying these parameters and repeatedly scanning the laser beam in a line across the samples, distinct coating layers are identified based on their spectral signatures. Additionally, the ablation process is analyzed to track the total ablation time required to remove each coating layer. The LIBS spectra obtained from the fs laser system are then compared with those from a high-power continuous wave laser system designed for industrial coating removal. The comparison highlights key differences in plasma formation, spectral characteristics, and signal quality between the two systems. These findings enhance the understanding of how laser parameters influence plasma generation and emission spectra during coating ablation, providing insights that could optimize LIBS-based elemental analysis for improved process monitoring and selective coating removal in industrial applications. • LIBS analysis of multilayer marine coatings. • Comparison between fs-LIBS and CW-LIBS. • Layer-by-layer discrimination using fs-LIBS. • Visual inspection of multilayer structure and fs ablation using mid-infrared optical coherence tomography.