Characteristics of the ablation plume induced on glasses for analysis purposes with laser-induced breakdown spectroscopy

Abstract

Laser-induced breakdown spectroscopy (LIBS) has been demonstrated as an efficient tool for elemental analyses of transparent dielectric materials such as glasses or crystals for more than ten years. The induced plasma is however much less studied compared to that induced on the surface of a metal. The purpose of this work is therefore to characterize the plasma induced on the surface of a glass sample for analytical purpose as a function of the ablation laser wavelength, infrared (IR) or ultraviolet (UV), and the ambient gas, air or argon. The surface damage of the samples was also observed for ablation with IR or UV laser pulse when the sample was a float glass or a frosted one. Optimized ablation fluence was then determined. The morphology of the plasma was observed with time-resolved spectroscopic imaging, while the profiles of the electron density and temperature were extracted from time- and space-resolved emission spectroscopy. The analytical performance of the plasmas was then studied in terms of the signal-to-noise ratio for several emission lines from some minor elements, Al, Fe, contained in glasses, and of the behavior of self-absorption for another minor element, Ca, in the different ablation conditions.