Laser-induced breakdown spectroscopy with improved spectral resolutions through the generation of high-temperature and low-density plasmas

摘要

Improved spectral resolutions were achieved in laser-induced breakdown spectroscopy (LIBS) through generation of high-temperature and low-density plasmas, A first pulse from a KrF excimer laser was used to produce particles by perpendicularly irradiating targets in air. A second pulse from a 532 ran Nd:YAG laser was introduced parallel to the sample surface to reablate the particles. Optical scattering from the first-pulse plasmas was imaged to elucidate particle formation in the plasmas. Narrower line widths (full width at half maximums: FWHMs) and weaker self-absorption were observed from time-integrated LIBS spectra. Estimation of plasma temperatures and densities indicates that high temperature and low density can be achieved simultaneously in plasmas to improve LIBS resolutions.