Infrared cavity ringdown laser absorption spectroscopy (IR-CRLAS) in low pressure flames

We report the first application of Infrared Cavity Ringdown Laser Absorption Spectroscopy (IR-CRLAS) as a diagnostic tool for combustion chemistry studies. The high sensitivity (10(-5) fractional absorption) and generality of IR-CRLAS for combustion studies is demonstrated for low pressure laminar flames and is shown to be robust even in sooting environments with high temperature gradients. The ability to obtain (1-D) spatially resolved spectra of both reactants and products within a narrow spectral region is also demonstrated. In these initial flame studies, two information rich mid-infrared spectral regions are probed at Doppler-limited resolution, centered about 1.5 mu m and 3.3 mu m.