Polarization- and time-resolved DFWM spectroscopy of the A 2Σ+− X 2Π (0,0) band transitions of nascent OH radicals generated by 266 nm laser photolysis of H2O2†

摘要: The potential of a non-linear spectroscopic technique – degenerate four-wave mixing (DFWM) spectroscopy for photo-dissociation studies is investigated. By applying carefully considered control the input beam polarizations, used to measure line shapes specific rovibrational transitions in A 2Σ+ − X 2Π (0,0) band nascent OH radicals upon pulsed H2O2. photofragmentation performed by linearly polarized radiation at 266 nm, and DFWM spectra are observed various time delays. In contrast linear methods, isotropic anisotropic components susceptibility tensor separately accessible using appropriate polarization geometries. particular, signals can be generated that exclusively due occurrence transient anisotropy recoil velocity angular momentum vector distributions fragments emerging from dissociation reaction. governed Doppler effect vectorial correlations between parent H2O2 molecule's transition dipole moment, fragments’ momentum, as well processes collision-induced rotational translational relaxation. Copyright © 2013 John Wiley & Sons, Ltd.