Emission intensity enhancement by re-ionization of Nd:YAG laser-produced plasma using a nitrogen laser

摘要

A dual-pulse laser-induced breakdown spectroscopic (DP-LIBS) technique for emission intensity enhancement is presented, using a Nd:YAG laser pulse to generate the plasma and a nitrogen laser pulse to enhance the degree of ionization in the laser-generated plasma plume. The higher degree of ionization with the nitrogen laser (337 nm) reveals significant enhancement of the signal intensity of several lead spectral lines. Besides the other advantages, the use of a nitrogen laser significantly reduces the experimental cost of DP-LIBS. The mechanism for the re-ionization of the laser-generated plasma plume by nitrogen laser has been discussed, and a comparison is presented of the plasma parameters in single-pulse and dual-pulse LIBS.