Spectra of spin-forbidden and spin-allowed transitions in the mixed b (3)Pi(u) approximately A (1)Sigma(u)(+) state of Na(2) are measured separately by two-photon excitation using a single tunable dye laser. The two-photon excitation produces Na(*)(3p) by photodissociation, which is easily and sensitively detected by atomic fluorescence. At low laser power, only the A (1)Sigma(u)(+) state is ex...

Arrays of ZnO/CdSSe core/shell nanowires with shells of tunable band gaps represent a class of interesting hybrid nanomaterials with unique optical and photoelectrical properties due to their type II heterojunctions and chemical compositions. In this work, we demonstrate that direct focused laser beam irradiation is able to achieve localized modification of the hybrid structure and chemical com...

The first application of the violet diode laser for laser induced fluorescence (LIF) detection in capillary electrophoresis is reported. Operating at 405 nm with an output power of 5 mW, this laser offers many advantages over conventional red diode lasers operating at 635 nm. We demonstrate the suitability of the violet diode laser for LIF detection by detecting amino acids labeled with naphtha...

We describe several laser fluorescence methods used to measure lead in flames and in post-flame gases. Each relies on excitation of the 7s P1 4 6p 2 3P0 transition from the ground state of lead and detection of fluorescence on the 7s P1 3 6p 2 P1 and 7s P1 3 6p 2 P2 transitions. Aqueous solutions of lead salts are atomized and injected into a lean flatflame. Dye laser excitation is used to dete...

Operating conditions for a tunable XeCl excimer laser have been optimized for tunable narrow-band operation at 222 nm with KrCl, formed in Kr/He/Ne/HCl gas mixtures. This wavelength is interesting for detection of nitric oxide (NO) in combustion environments. The laser emission coincides with the (1, 1) and (2, 2) bands of the NO A-X system. Laser-induced-fluorescence spectra taken in a flame s...

Terahertz (THz) wave science and technology have been found countless applications in biomedical imaging, security screening, and non-destructive testing as they approach maturity. However, due to the challenge of high ambient moisture absorption, the development of remote open-air broadband THz spectroscopy technology is lagging behind the compelling need that exists in homeland security, astr...

This study is concerned with the measurements of scalar variables in turbulent flows, by Laser Induced Fluorescence. We used solutions of water and rhodamine B, to study the properties of the fluorescent tracer and the characteristics of the fluorescence signal and its dependence on the instrumentation and other experimental conditions. It is shown that a linear relationship between light inten...

Sludge applications have been used to maintain fertility of agricultural soils without damaging the natural ecosystem. The aim of this study was evaluating the influence of sewage-sludge addition on the quality of organic matter (OM) of a Brazilian Oxisol by Laser Induced Fluorescence (LIF). LIF was used to analyze OM of whole soil and different soil fractions separated by chemical and physical...