Spontaneous vibrational Raman scattering (VRS) is produced by a broadband excimer laser at 248 nm (KrF) in a H2–air flame and VRS spectra are recorded for lean, stoichiometric, and rich flames. Except at very lean flame conditions, laser-induced fluorescence (LIF) processes interfere with VRS Stokes lines from H2, H2O, and O2. No interference is found for the N2 Stokes and N2 anti-Stokes lines. In a stoichiometric H2/air flame, single-pulse measurements of N2 concentration and temperature (by the VRS Stokes to anti-Stokes ratio) have relative standard deviation of 7.7 and 10%, respectively. These single pulse measurement errors compare well with photon statistics calculations using measured Raman cross sections.
© 1990 Optical Society of America
Original Manuscript: June 20, 1989
Published: May 20, 1990
Robert W. Pitz, Joseph A. Wehrmeyer, J. M. Bowling, and Tsarng-Sheng Cheng, "Single pulse vibrational Raman scattering by a broadband KrF excimer laser in a hydrogen–air flame," Appl. Opt. 29, 2325-2332 (1990)