Abstract

Flame radicals are fragments of molecules with high reactivity and control the process of combustion to a high degree. Therefore, the knowledge of accurate number densities of these species is very important. Laser-induced fluorescence (LIF) spectroscopy is one of the most sensitive optical techniques for the accurate determination of concentrations and temperatures. Because quenching effects reduce the fluorescence yield in flame experiments considerably, picosecond laser excitation and recording the fluorescence in a picosecond time scale is known to improve the sensitivity of the LIF method considerably.^1,2 For a quantitative data analysis laser-induced polarization effects, photodissociation, photoionization, and multiphoton processes have to be considered.^2,3

© 1996 Optical Society of America