Nanosecond laser preheating effect on ablation morphology and plasma emission in collinear dual-pulse laser-induced breakdown spectroscopy

Abstract

A focus-offset collinear dual-pulse laser-induced breakdown spectroscopy (FOC-DP-LIBS) is designed and used to investigate the laser ablation and spectral intensity with an aluminum alloy sample. The laser crater morphologies and ablation volumes were measured. An inter pulse time delay dependent ablation efficiency on a nanosecond laser heated sample was observed, which was similar to the trend of spectral intensity versus inter pulse time delay in the delay time less than 3 s. Based on the observation, the nanosecond pulse laser pre-heating effect on subsequent second laser ablation and signal enhancement is discussed, which will be helpful for understanding the ablation and signal enhancement mechanism in standard collinear DP-LIBS technique.

Multiple-element analysis of coal using collinear double-pulse laser-induced breakdown spectroscopy

“…Although the energy of the first laser pulse was 5 mJ and could not ablate the target and generate a plasma, the signal enhancement was also observed contributing to the conditions changed by the first laser pulse. 33…”

“…The signal enhancement could be attributed to both the improved coupling effect of the preplasma and the target with the second laser pulse. 32,33 The pre-plasma could be reheated and re-excited by the second laser pulse, resulting in a higher excitation efficiency of the ablated mass and an increased plasma temperature. On the other hand, the rst laser pulse signicantly inuenced the environmental conditions of the interaction between the second laser pulse and the sample surface.…”

Quantitative analysis of Cr in soil using laser induced breakdown spectroscopy combined with relevance vector machine method

“…In LIBS analysis, first high-energy pulse laser is used to ablate the sample and generate plasma; second, analyzing the characteristic spectrum of atomic and ionic radiation in the high-temperature laser plasma, the element composition and concentration are then obtained from the position of analysis lines and signal intensity [2][3][4]. This technology has been widely used in food safety, environmental testing, archaeological identification, industrial applications and other fields [5][6][7][8][9].. Traditionally, basic calibration method and internal calibration method [10,11] are widely used in the quantitative analysis of laser induced breakdown spectroscopy, but the analytical accuracy and repeatability is not very satisfactory.…”