Laser-Induced Fluorescence Measurement of Free Radical Intermediates

Laser-induced fluorescence (LIF) provides a means for sensitive, selective and nonintrusive measurements of reactive intermediates, often free radicals, which control the chemistry of combustion. The same approach can be used to detect in the gas phase, atoms, radicals and ions which are reactive intermediates in materials processing. This article briefly examines the use of LIF in combustion. It includes a description of the LIF spectroscopic method as employed for quantitative measurements, and the use of LIF in a semiquantitative manner with extension to the simultaneous detection of more than one species.