An optical transition of atomic iron can be used to build a two-dimensional absorption filter that operates in the tuning range of a narrow-band KrF excimer laser (0.05-cm−1 bandwidth). Iron atoms with a number density of 2 × 1013 cm−3 are produced by thermal dissociation of iron pentacarbonyl [Fe(CO)5]. With this filter it is possible to discriminate Mie and surface-scattered light against Rayleigh scattering. For Rayleigh scattering from the exhaust gas of a methane–air flame at a measured temperature of 1970 K, the ratio of transmission for Rayleigh scattering to transmission for Mie scattering is 16.8. Single-shot scattering from the exhaust gas of a high-pressure burner is presented as an application.
© 1996 Optical Society of America
P. Gölz and P. Andresen, "Atomic vapor filter for two-dimensional Rayleigh imaging experiments with a narrow-band KrF excimer laser," Appl. Opt. 35, 6054-6061 (1996)