Optical emission and energy disposal characterization of the laser ablation process of CaF2, BaF2, and NaCl at 1064 nm

M. VILLAGRAN-MUÑIZ,H. SOBRAL, C. A. RINALDI,I. CABANILLAS-VIDOSA, AND J. C. FERRERO

JOURNAL OF APPLIED PHYSICS

AMER INST PHYSICS

Año: 2008 vol. 104 p. 112 - 117

0021-8979

A method to simultaneously measure the fraction of incident energy spent as absorbed, scattered, and consumed energy by the plasma generated in the ablation process is presented. The resultsobtained allowed to make an energy balance in the ablation process of halogenated earth alkaline metal crystals ͑NaCl, BaF2, and CaF2͒ and to relate the nature of the crystal structure to the absorbedenergy. The latter could be determined by monitoring the magnitude of the breakdown induced by the discharge between the plates of a capacitor. Simultaneously, time resolved optical emissionspectroscopy was used to analyze the ion emission intensity and as a function of the energy absorbedby the sample. This plot shows the usual sigmoid behavior for the ablation process with the threetypical regions, corresponding to the vaporization, screening, and ablation regimes. A heuristic equation has been used to analyze this process in terms of the nature of the crystal structure. Fromthis equation the critical absorbed energy for each of the studied samples could also be determined.