The CO formation as a result of the CO<sub>2</sub> photodissociation at 230.08 nm was observed by using the two-photon laser-induced fluorescence (LIF) method. The measurements were performed in a propane–air combustion product flow and in mixtures of CO<sub>2</sub> and O<sub>2</sub>. The temperature dependence of the fluorescence signal caused by CO molecules, produced in the photodissociation of CO<sub>2</sub> molecules under the action of laser radiation at a wavelength of 230.08 nm, was measured at temperatures ranging from 1300 to 2000 K. It is shown that consideration of CO<sub>2</sub> photodissociation under the action of the probing radiation is necessary when one applies the two-photon LIF method for the measurement of small CO concentrations in high-temperature gas mixtures containing CO<sub>2</sub>. As an example, a correction is given of the CO concentration profiles measured by the LIF method in the combustion product flow around a cooled metallic plate.
© 1998 Optical Society of America
(120.0120) Instrumentation, measurement, and metrology : Instrumentation, measurement, and metrology
(120.1740) Instrumentation, measurement, and metrology : Combustion diagnostics
(260.5130) Physical optics : Photochemistry
(300.2530) Spectroscopy : Fluorescence, laser-induced
Anatoli P. Nefedov, Vladimir A. Sinel’shchikov, Alexander D. Usachev, and Andrei V. Zobnin, "Photochemical Effect in Two-Photon Laser-Induced Fluorescence Detection of Carbon Monoxide in Hydrocarbon Flames," Appl. Opt. 37, 7729-7736 (1998)