Energy transfer in the OH A2sigma+ state: the role of polarization and of multi-quantum energy transfer.

Energy transfer in the excited state of molecules including quenching, rotational and vibrational energy transfer, and polarization scrambling is one of the major factors which limit the accuracy of laser-induced fluorescence (LIF) measurements. In this contribution, we present time-, wavelength-, and polarization-resolved spectra of OH in a stoichiometric H2/air flame at atmospheric pressure. Emphasis is placed on the investigation of the role of polarization effects and of multi-quantum vibrational energy transfer on fluorescence spectra originating from the OH A2sigma+ state. Results are compared to simulations using a rate-equation model (LASKIN) developed in our group.