Article

Use of broadband, continuous-wave diode lasers in cavity ring-down spectroscopy for liquid samples.

Department of Chemistry, Stanford University, Stanford, California 94305-5080, USA.
Applied Spectroscopy (Impact Factor: 1.94). 06/2003; 57(5):571-3. DOI: 10.1366/000370203321666614
Source: PubMed

ABSTRACT Cavity ring-down spectroscopy (CRDS) is an extremely sensitive absorption technique that has been applied primarily to gas samples, which are characterized by having narrow absorption features. Recently, CRDS has also been applied to liquid samples, which have broad absorption features. The use of small inexpensive diode lasers as light sources for liquid samples is demonstrated. The low cost coupled with the ease and technical straightforwardness of application gives this technique wide appeal.

0 Bookmarks
 · 
118 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Continuous-wave (cw) cavity-ringdown (CRD) spectroscopy provides a highly sensitive way to measure optical absorption by observing the decay rate of light from a high-finesse optical cavity containing the sample of interest (usually gas-phase molecules). In rapidly swept cw-CRD spectroscopy, optical build-up and subsequent ringdown decay are initiated by rapidly sweeping the cavity length or the wavelength of the monochromatic tunable cw laser radiation, thereby establishing and interrupting optical resonance between the laser light and the longitudinal-mode frequencies of the cavity. We review the experimental methodology and applications of this technique, indicating its advantages and prospects for spectroscopic sensing.
    Chemical Physics Letters 01/2011; 512(1):1-20. · 2.15 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Plasma-cavity ringdown spectroscopy (P-CRDS) was first introduced for trace elemental measurements in 1997. During the last decade, this technique has rapidly advanced from the initial demonstration of the basic concept to the latest (prototype) instrumentation. P-CRDS has been demonstrated to be a powerful technique for ultra-sensitive elemental and isotopic analysis of trace metals, radionuclides, and isotopes existing in solid, vapor, and/or liquid phases. Utilizing various plasma sources, such as an inductively coupled plasma (ICP), a microwave-induced plasma (MIP), and a tube-shaped MIP, and different laser sources, namely, pulsed and continuous wave lasers, several elements and isotopes, including Pb, 238U, 235U, Hg, Sr, and Mn, as well as the fine structures of Hg, have been measured with P-CRDS, and the detection limits have ranged from μg mL−1 to pg mL−1 levels. This paper presents a critical review of the P-CRDS technique with an emphasis on its application in elemental and isotopic analysis. Some critical issues encountered in the application of P-CRDS and its technological development during the last ten years, such as sensitivity, spectral interference, plasma optimization, evolution of plasma sources, laser beam behavior in the plasma, laser source effects, and instrument configurations are discussed. Technological and scientific barriers to be overcome for eventual instrumentation in the field of atomic/isotopic spectrometry, including (1) portable UV laser sources, (2) novel plasma sources, and (3) detection of multiple analytes, are also discussed.
    Journal of Analytical Atomic Spectrometry 01/2007; 22(11). · 3.40 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A new application of incoherent broad-band cavity enhanced absorption spectroscopy (IBBCEAS) to weak transitions in solution through a very straightforward modification of commercially available double-beam UV/VIS absorption spectrometers is reported. The improved sensitivity of the new approach is demonstrated on basis of the weak Franck-Condon inhibited absorption of the fifth C-H stretch overtone in liquid benzene. The theoretical limits of the enhancement of the signal-to-noise ratio of IBBCEAS in comparison with single pass absorption experiments are discussed for a set of given experimental cavity parameters. The optical loss properties of a typical transparent cuvette window in the cavity are also discussed.
    Review of Scientific Instruments 01/2005; 76. · 1.60 Impact Factor

Full-text (2 Sources)

Download
32 Downloads
Available from
May 21, 2014