Confocal controlled LIBS microscopy with high spatial resolution and stability

Abstract

A novel confocal controlled laser-induced breakdown spectroscopy (CCLIBS) microscope is proposed to improve the spatial resolution and stability of LIBS-based imaging. The microscope uses the light reflected from the sample illuminated by a continuous-wave laser, to construct a laser confocal system with high focusing ability, ensuring high spatial resolution three-dimensional (3D) morphological measurement of the sample. Then, the LIBS signals are excited by a pulsed laser through the common light path to achieve multiple element detection of the sample, thereby realizing 3D elemental imaging with high spatial resolution and anti-drift properties. We demonstrate the focusing ability (20 nm), operating speed (6 Hz) and the lateral resolution of the morphological and elemental images (700 nm and 10 μm, respectively), which significantly improves the spatial resolution and provides an inherent anti-drift capability. 3D multi-elemental maps of Ti, Ba, Ca, Fe and Na with 10 μm lateral resolution are demonstrated in the CCLIBS imaging configuration. These results provide new prospects for both conventional LIBS and LIBS-based imaging in various application fields.