Sensitive alloy elemental analysis under minimal sample ablation with target-enhanced orthogonal double-pulse laser-induced breakdown spectroscopy using a dielectric target

Abstract In order to realize sensitive elemental analysis of alloy samples under minimal sample ablation, target-enhanced orthogonal double-pulse laser-induced breakdown spectroscopy (TEODP-LIBS) using a dielectric target was developed. In this technique, the reheating laser in conventional orthogonal double-pulse laser-induced breakdown spectroscopy (ODP-LIBS) was focused on the target surface to produce target plasma; the optical emission intensity of the sample elements could be significantly enhanced through the interaction between target plasma and sample plasma. In order to reduce the spectral interference from the target material, a dielectric potassium bicarbonate (KHCO3) target was selected. 8–15 folds signal enhancement were achieved using target enhancement. The detection limits of copper and chromium in aluminum alloy obtained by TEODP-LIBS were improved by a factor of 5.1 and 8.8 compared with that obtained by ODP-LIBS. It is demonstrated that TEODP-LIBS using a dielectric target is very useful for sensitive elemental analysis of alloy samples under minimal sample ablation with reduced spectral interference.