Article

Temporally and spectrally resolved imaging of laser-induced plasmas.

Laser Processing Group, Instituto de Optica, Consejo Superior de Investigaciones Cientificas, Serrano 121, 28006 Madrid, Spain.
Optics Letters (Impact Factor: 3.18). 11/2004; 29(19):2228-30. DOI: 10.1364/OL.29.002228
Source: PubMed

ABSTRACT We report a hybrid imaging technique capable of performing measurements of the spatial, temporal, and spectral emission characteristics of laser-induced plasmas by use of a single detection system. We apply this technique to study the plasma produced by laser ablation of LiNbO3 and observe phenomena not seen in such detail with standard instruments. These include extreme line broadening up to a few nanometers accompanied by self-absorption near the target surface, and expansion dynamics that differ strongly between the different species. Overall, the wealth of quantitative information provided by this novel technique sheds new light on processes occurring during plasma expansion.

0 Bookmarks
 · 
65 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this work is to demonstrate that single-photon photoionization processes make a significant difference in the expansion and temperature of the plasma produced by laser ablation of ceramic Al2O3 in vacuum as well as to show their consequences in the kinetic energy distribution of the species that eventually will impact on the film properties produced by pulsed laser deposition. This work compares results obtained by mass spectrometry and optical spectroscopy on the composition and features of the plasma produced by laser ablation at 193 nm and 248 nm, i.e., photon energies that are, respectively, above and below the ionization potential of Al, and for fluences between threshold for visible plasma and up to ≈2 times higher. The results show that the ionic composition and excitation of the plasma as well as the ion kinetic energies are much higher at 193 nm than at 248 nm and, in the latter case, the population of excited ions is even negligible. The comparison of Maxwell-Boltzmann temperature, electron temperatures, and densities of the plasmas produced with the two laser wavelengths suggests that the expansion of the plasma produced at 248 nm is dominated by a single population. Instead, the one produced at 193 nm is consistent with the existence of two populations of cold and hot species, the latter associated to Al+ ions that travel at the forefront and produced by single photon ionization as well as Al neutrals and double ionized ions produced by electron-ion impact. The results also show that the most energetic Al neutrals in the plasma produced at the two studied wavelengths are in the ground state.
    Journal of Applied Physics 06/2013; 113(22). · 2.19 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In order to characterize the spatial distribution of the laser induced plasma in the round, two aspects of the oriented expansion were investigated. The one dimensional distribution was illustrated by the spectroscopy, and the speed of the plasma was estimated from the time-of-flight curves. The angular distribution function was obtained by a derived formula and an experimental result for deposition of Hg0.8Cd0.2Te thin film.
    Physics of Plasmas 04/2012; 19(4). · 2.25 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The dynamics and the reactivity of the plasma produced during pulsed laser ablation of LiNbO3 have been investigated. Optical emission spectroscopy combined with time-gated imaging with high spatial resolution is applied to the study of the factors that influence the plasma expansion process, the dynamics of the ejected species the influence of a background atmosphere (O2 and Ar) and the reactivity of the expanding plasma. Direct evidence for O2 dissociation occurring during expansion is presented and the temporal evolution of the spatial distribution of the dissociated O2 is studied in detail. The influence of dissociation and velocities of the ablated species on the quality of thin films grown by pulsed laser deposition are discussed.
    Applied Physics Letters 01/2005; 87(21):211501-211501-3. · 3.52 Impact Factor

Full-text (2 Sources)

Download
29 Downloads
Available from
Jun 2, 2014