Picosecond laser-spectroscopy measurement of hydroxyl fluorescence lifetime in flames

Abstract

Data are reported for the first known application of picosecond laser spectroscopy to the measurement of collisional quenching rates by time-resolved laser-induced fluorescence in flames. Collisional quenching rates are important for the determination of species concentrations by laser-induced fluorescence. The collisional quenching lifetime following excitation of the R(2)(4) A(2)Sigma(+) (nu' = 0) ? X(2)II (nu'' = 0) transition was measured to be 1.8 nsec in the burned-gas region of an atmospheric-pressure, premixed methane-air flame.