Article

Polarization-resolved laser-induced breakdown spectroscopy.

Department of Chemistry, University of Illinois, Chicago, Illinois 60607-7061, USA.
Optics Letters (Impact Factor: 3.39). 03/2009; 34(4):494-6. DOI: 10.1364/OL.34.000494
Source: PubMed

ABSTRACT It is shown that plasma polarization measurements can be used to enhance the sensitivity of laser-induced breakdown spectroscopy (LIBS). The polarization of the plasma emission is used to suppress the continuum with only slight attenuation of the discrete atomic and ionic spectra. The method is demonstrated for LIBS detection of copper and carbon samples ablated by pairs of femtosecond laser pulses.

0 Bookmarks
 · 
107 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Polarization of the plasma luminescence produced by both nanosecond and femtosecond laser ablation of Si(111) was analyzed under different conditions of fluence and detection geometry. It is shown that the luminescence is partially polarized and is directed in the plane of the crystal. The time evolution of the plasma emission signal was also investigated with the use of a streak camera. The mechanism for polarization is proposed to be preferential reflection of s-polarized light (i.e., light polarized normal to the plane of laser incidence) by the melted surface, in agreement with the Fresnel equations. Earlier reports of much stronger polarization are shown to be erroneous.
    Spectrochimica Acta Part B Atomic Spectroscopy 01/2012; · 3.14 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Dual-pulse (DP) laser-induced breakdown spectroscopy (LIBS) provides significant improvement in signal intensity as compared to conventional single-pulse LIBS. We investigated collinear DPLIBS experimental performance using various laser wavelength combinations employing 1064 nm, 532 nm, and 266 nm Nd:YAG lasers. In particular, the role of the pre-pulse laser wavelength, inter-pulse delay times, and energies of the reheating pulses on LIBS sensitivity improvements is studied. Wavelengths of 1064 nm, 532 nm, and 266 nm pulses were used for generating pre-pulse plasma while 1064 nm pulse was used for reheating the pre-formed plasma generated by the pre-pulse. Significant emission intensity enhancement is noticed for all reheated plasma regardless of the pre-pulse excitation beam wavelength compared to single pulse LIBS. A dual peak in signal enhancement was observed for different inter-pulse delays, especially for 1064:1064 nm combinations, which is explained based on temperature measurement and shockwave expansion phenomenon. Our results also show that 266 nm:1064 nm combination provided maximum absolute signal intensity as compared to 1064 nm:1064 nm or 532 nm:1064 nm.
    Spectrochimica Acta Part B Atomic Spectroscopy 05/2013; 87:43-50. · 3.14 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: It is shown that the continuum emission produced by an Al alloy ablated by femtosecond laser pulses is much more polarized than the characteristic lines of elements. A Glan—Thomson polarizer is used in the laser-induced breakdown spectroscopy experiment to investigate the polarization effect. The use of the polarizer at its minimal transmission increases the signal-to-noise ratio. The effects of angle of detection, focal position, and pulse energy on the signal-to-noise ratio are also studied.
    Chinese Physics B 01/2012; 21(7). · 1.15 Impact Factor

Full-text

View
1 Download
Available from