Double-pulse and calibration-free laser-induced breakdown spectroscopy at low-ablative energies.

The use of double-pulse laser-induced breakdown spectroscopy (DP-LIBS) in quantitative analysis generally depends on standards and calibration curves. To our knowledge, in this Letter, we report the first quantitative analysis based on DP-LIBS at low ablative energies with a self-calibrated method. We compare the effects of plasmas on the calibration-free LIBS technique, generated by DP-LIBS, and the traditional single-pulse (SP) LIBS on a steel sample. Our analyses reveal that when SP-LIBS and DP-LIBS reach comparable emission line intensities, plasma parameters and quantitative analysis are practically the same for both experiments. Additionally, we report the behavior of the emission enhancement of some elements (Fe and Cr) at low ablative pulse energies (0.2-8 mJ) using the orthogonal reheating DP-LIBS configuration.