Quantitative Multi-Element Analysis in Soil Using 532 nm and 1064 nm Lasers in LIBS Technique

Plasma Chemistry and Plasma Processing - Laser-induced breakdown spectroscopy (LIBS) has been considered a promising tool for agricultural analysis in the recent years due to its advantages over...     

Femtosecond laser ablation on dental hard tissues—Analysis of ablated profile near an interface using local effective intensity

This study evaluated the process of ablation produced by a Ti:Sapphire femtosecond laser under different average powers taking place at the enamel/dentin interface. Based on the geometry of ablated microcavities the effective intensity for ablation was obtained. This study shows the validity for the local effective intensity analysis and allows a quantification of the variation in the ablation geometry taking place at the interface of two naturally different materials. It shows that the variation of the diameter of the ablated region as a function of the cavity depth comes essentially from a mechanism of effective intensity attenuation, as a result of a series of complex effects. Additionally, our data are sufficient to predict that a discontinuity on the ablation profile will occur on the interface between two biological media: enamel-dentin, showing a suddenly jump on the ablated cavity dimensions.     

Time progression of ultrashort laser ablation in a transparent material

Laser ablation on the ultra-short-pulses regime (femtosecond), has an impact on materials processing and micromachining in a quite profound ways. The investigation of the time progression of the laser ablation process within the material can produce much information and it is not conventionally used. The implementation of such study is the main aim of this paper. The temporal dependence of the diameter and depth of micro-drilling in the sample was verified, beyond the simple understanding of the mechanism for plasma generated during the ablation. From the monitoring of the time progression of the ablation, the time dependence for the velocity of ablation had been determined. In most cases, fume attenuation of the incoming laser beam and fume escape paths, produce dominant influence the characteristics of the region ablated. The method here employed is simple and can be carried out in real time without interruption of the process. In the implemented method light scattered from an auxiliary source allow visualization and record of the ablated geometry as it progress.