Laser-induced fluorescence has been shown to be a very sensitive technique for trace analysis. The problem of scattered light, i.e., radiation coming from unvaporized particles in the flame, has been considered a major problem in the use of resonance fluorescence as an analytical technique. Various methods have been developed for eliminating or at least accounting for scattering, and these methods have been reviewed in detail. One of the most recent of these techniques is that of polarization spectroscopy, developed by Wieman and Hansch for Doppler-free, high-resolution studies. Tong and Yeung applied the technique to a flame for the first time, obtaining limits of detection of 0.03 and 37 ng/L for Na and Ba, respectively. The work, however, required the use of a frequency-stabilized, Ar-ion, pumped, ring dye laser. For the technique to be analytically useful, i.e., applicable to a wide range of elements, it should be possible to use a pulsed dye laser. We report here the first application of a pulsed dye laser to this technique.
J. A. Lanauze and J. D. Winefordner, "Application of a Pulsed Dye Laser to Polarization Spectroscopy for Elemental Analysis," Appl. Spectrosc. 40, 709-711 (1986)