Quantitative two-photon LIF imaging of carbon monoxide in combustion gases

Abstract
Two-dimensional imaging of CO concentration in combustion gases is demonstrated using two-photon-excited planar laser-induced fluorescence. A quantitative model is presented for the simultaneous two-photon excitation of several rotational transitions of the B1+X1+ system and the subsequent visible fluorescence (B1+A1Π). The model is verified by comparison of predicted and measured excitation spectra and of temperature-corrected relative fluorescence measurements to standard probe measurements of the center line CO distribution in a CO–air diffusion flame. In addition, CO imaging experiments in a premixed methane–air flame indicate the production of C2 by laser photodissociation of acetylene.