Improvement of the spatial resolution of the spatial mapping of metallic coatings by using picosecond LIBS

Laser-induced breakdown spectroscopy (LIBS) has been widely applied in various fields such as environmental monitoring, materials science, and archaeological research. The current research focuses on improving the spatial resolution of elemental spatial imaging by using LIBS. The nanosecond laser is commonly used in LIBS. During the nanosecond laser ablation process, there is a thermal effect on the target material, making it difficult to further improve the spatial resolution. This study used a picosecond laser to investigate the effects of the diameter of laser focusing spot, laser energy, and laser irradiation interval on the spatial resolution of LIBS. The spatial mapping of metallic coatings by using LIBS with a spatial resolution of 1 μm was achieved by using laser energy of 0.4 μJ/pulse and irradiation interval of 0.8 μm. The LIBS measurement results are in good agreement with the scanning electron microscopy energy dispersive X-ray spectroscopy (SEM-EDS) results. This research shows that by changing the laser ablation conditions, the spatial resolution of the spatial mapping of metallic coatings by using LIBS based on picosecond laser can be reduced to 1 μm or lower.