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

Two-dimensional imaging of CO concentration in combustion gases is demonstrated using two-photonexcited planar laser-induced fluorescence. A quantitative model is presented for the simultaneous twophoton excitation of several rotational transitions of the B(1)Sigma(+) ? X(1)Sigma(+) system and the subsequent visible fluorescence (B(1)Sigma(+) ? A(1)Pi). 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 C(2) by laser photodissociation of acetylene.