Comparison of two-photon excitation schemes for CO detection in flames

Two approaches for CO concentration measurement in premixed and non-premixe d hydrocarbon/air flames based on two-photon laser excitation and subsequen t detection of induced fluorescence are compared in derail. It is shown tha t excitation of the C(1)Sigma <--<-- X(1)Sigma (+) band of CO indicates sig nificant advantages over the commonly used B(1)Sigma <--<-- X(1)Sigma (+) b and of the Hopfield-Birge system with respect to crosstalk of simultaneousl y excited laser-induced fluorescence of C-2. The measurements demonstrate t hat both approaches give comparable signal intensities and are similarly in fluenced by multi-photon ionization.