Time-resolved spectroscopy of femtosecond laser-induced Cu plasma with spark discharge

Abstract

The combination of spark discharge and laser-induced breakdown spectroscopy (LIBS) is called spark discharge assisted LIBS. It works under laser-plasma triggered spark discharge mode, and shows its ability to enhance spectral emission intensity. This work uses a femtosecond laser as the light source, since femtosecond laser has many advantages in laser-induced plasma compared with nanosecond laser, meanwhile, the study on femtosecond LIBS with spark discharge is rare. Time-resolved spectroscopy of spark discharge assisted femtosecond LIBS was investigated under different discharge voltages and laser energies. The results showed that the spectral intensity was significantly enhanced by using spark discharge compared with LIBS alone. And, the spectral emission intensity using spark discharge assisted LIBS increased with the increase in the laser energy. In addition, at low laser energy, there was an obvious delay on the discharge time compared with high laser energy, and the discharge time with positive voltage was different from that with negative voltage.

Highly sensitive analysis of trace elements in aqueous solutions using surface-enhanced and discharge-assisted laser-induced breakdown spectroscopy

“…The temperature and electron density of the Al plasma with the spark discharge were higher than those of the Al plasma without the spark discharge, thereby realizing the re-excitation of the Al plasma. 28–31,33–36 Then more atoms and ions were excited to upper electronic states by discharge-assisted LIBS. Obviously, the heavy metal elements in the Al plasma were also excited to upper electronic states.…”

“…The stability of the discharge is affected by the surface roughness of the sample, and high-voltage and high-current power supplies are also harmful to people. 27 For these reasons, researchers use a specific energy pulsed laser to ablate the sample to be tested, and then use spark discharge to further breakdown the laser-plasma to achieve the purpose of improving spectral intensity, analytical sensitivity, the signal-to-background ratio, and spatial resolutions; 28–31 this method is called discharge-assisted LIBS. It can be seen that spark discharge is an important factor affecting spectral emission.…”

Effect of gold nanoparticle concentration on spectral emission of AlO molecular bands in nanoparticle-enhanced laser-induced Al plasmas

“…[4][5][6][7][8][9] Therefore, improving the signal intensity of LIBS to increase the detection sensitivity and reduce the detection limit has become a hot topic of LIBS technology research. LIBS signal enhancement techniques mainly include double-pulse LIBS, 10,11 spark-discharged LIBS, 12,13 magnetic connement LIBS, 14,15 spatial connement LIBS, 16,17 and other methods. The applications of these techniques are limited because they require additional devices with complex structures or elevated costs.…”

Influence of distance from lens to sample surface on spectral sensitivity of femtosecond laser-induced breakdown spectroscopy with NaCl water film

“…Enhanced laser-induced plasma emission intensity is the main way to make up for these disadvantages of LIBS technology. Based on solid samples, researchers believe that many methods, including double-pulse [19], spatial confinement [20][21][22], magnetic confinement [23], spark discharge enhancement [24][25][26][27], increasing sample temperature [28][29][30][31], changing the distance from lens to sample surface (DFLS) [32][33][34], can improve the stability and analytical sensitivity of liquid samples. Among them, the doublepulse method is frequently applied to the detection of liquid samples.…”