ATOMIC VAPOR FILTER FOR 2-DIMENSIONAL RAYLEIGH IMAGING EXPERIMENTS WITH A NARROW-BAND KRF EXCIMER-LASER

An optical transition of atomic iron can be used to build a two-dimens ional absorption filter that operates in the tuning range of a narrow- band KrF excimer laser (0.05-cm(-1) bandwidth). Iron atoms with a numb er density of 2 x 10(13) cm(-3) are produced by thermal dissociation o f iron pentacarbonyl [Fe(CO)(5)]. With this filter it is possible 60 d iscriminate Mie and surface-scattered light against Rayleigh scatterin g. For Rayleigh scattering from the exhaust gas of a methane-air flame at a measured temperature of 1970 K, the ratio of transmission for Ra yleigh scattering to transmission for Mie scattering is 16.8. Single-s hot scattering from the exhaust gas of a high-pr-ensure burner is pres ented as an application. (C) 1996 Optical Society of America