ONE-DIMENSIONAL IMAGING OF H-2 DENSITIES AND OF TEMPERATURES VIA ROTATIONAL RAMAN-SCATTERING OF NARROW-BAND, 248 NM, LASER-LIGHT

It is demonstrated that the well known rotational Raman spectrum of H- 2 can be used to find the relative densities of hydrogen and the gas t emperature as a function of position, A line-shaped beam from a tunabl e excimer laser intersects H-2-air flames, Scattered light is acquired with an imaging spectrograph, This produces both Stokes and anti-Stok es spectra. By adjusting the laser beam's polarization, the interferin g Rayleigh intensity is sufficiently reduced without the use of a filt er, The temperature measurements can be from below room temperature to about 1200 K. The method also works at temperatures > 1200 K, but the use of vibrational Raman spectroscopy is probably better there, Also shown is an image that has simultaneously acquired, spatially resolved spectra from rotational Raman, vibrational Raman and laser-induced fl uorescence, Such combined information might be used to diagnose a gaeo us system in some detail. (C) 1997 John Wiley & Sons, Ltd.