Concentric multipass cell enhanced double-pulse laser-induced breakdown spectroscopy for sensitive elemental analysis

摘要

Although double-pulse laser-induced breakdown spectroscopy (DP-LIBS) is regarded as a promising technique in trace element analysis, its limit of detection (LOD) is not sufficient for some applications. The enhancement of spectral signal is the key to further improve the sensitivity of DP-LIBS. To further increase the sensitivity of DP-LIBS, a concentric multipass cell (CMC) enhanced DP-LIBS (CMC-DP-LIBS) technique is proposed for the first time, which makes full use of the energy of reheating laser by multi-reflection in CMC to enhance the spectral signal and lower LOD. 2.3 times signal enhancement of Mn I 403.08 nm line and 2.3 times decrease of LOD of Mn on the surface of zinc bulk compared with traditional orthogonal reheating DP-LIBS were attained. The signal enhancement factor can reach to 3.6 theoretically with the increase of reflectivity and the sizes of mirrors of CMC. This CMC-DP-LIBS provides a new approach to further improve the sensitivity of DP-LIBS and promotes its application in trace element detection.