Single laser based dual-wavelength ablation technique for emission enhancement during LIBS

Abstract

In this paper, a novel method of the dual-wavelength (laser-induced breakdown spectroscopy LIBS) technique using a single laser system is proposed and demonstrated. Experiments are performed using a pulsed Nd3+ : YAG laser with a pair of 355–1064 nm and also with 532–1064 nm. The shorter wavelength laser is used for ablation and plasma formation, and the fundamental wavelength (1064 nm) is used for plasma re-excitation. The proposed dual-wavelength LIBS technique is used for lunar simulant samples under different ambient pressure conditions. Various characteristic parameters, such as the emission line-intensity enhancement, plasma temperature, lifetime and plasma area, are studied. Experimental studies clearly showed the emission line-intensity enhancement up to a factor of 3. Emission lifetime showed a longer sustained emission with an increase of up to 33% for the dual-wavelength approach. A theoretical simulation based on the hydrodynamic equations is also performed for dual-wavelength ablation and re-excitation. The estimated plasma temperature and ablation plume-front velocity clearly showed an increase in dual wavelength, which is in agreement with the experimental results.

Detecting Temporal Changes of Self-Absorption in a Laser-Induced Copper Plasma from Time-Resolved Photomultiplier Signal Emission Profiles

“…used a combination of a fast PMT-high bandwidth oscilloscope to obtain the temporal evolution of a plasma obtained on simulant lunar soil. 21…”

Microanalysis of silver jewellery by laser-ablation laser-induced breakdown spectroscopy with enhanced sensitivity and minimal sample ablation

“…It is worthwhile to compare Antony's work reported in Ref. [28] with this work. Although both works adopted 532+1064-nm wavelength combination based on single Nd:YAG laser, 1064-nm laser certainly contributed to sample ablation thus deteriorate the spatial resolution in Antony's work due to cross beam geometrical arrangement; however, in this work, 1064-nm laser did not ablate any samples during the reheating process, this ensured a high spatial resolution which was only determined by 532-nm laser due to orthogonal geometrical arrangement.…”

“…In most of the DP-LIBS studies mentioned above, researchers paid less attention on spatial resolution improvement than on signal enhancement and two laser systems were usually required. Antony et al [28] reported a cross beam DP-LIBS for analysis of lunar simulant samples in which only single Nd:YAG laser was required. In their experiment, 532-nm laser from one Nd:YAG laser was used to ablate sample and 1064-nm laser from the same laser was used to reheating the plasma to get enhance plasma emission.…”

Radon decay monitoring in air using characteristic emission of species in metal-assisted LIBS

“…The enhancement mainly arises from the metastable excited state of helium atom which is utilized to induce the delayed excitation of hydrogen atoms during ablation. On the other hand, the methods of preheating and reheating of plasma using dual lasers have been used to enhance the characteristic emissions at the expense of the background noise elevation (Babushok et al, 2006;Shoursheini et al, 2009Shoursheini et al, , 2010Killinger et al, 2007;Antony et al, 2012).…”