Two-photon dissociation of H2O and D2O at 266 nm

Abstract

Polarisation of the fluorescence from A ²Σ⁺ OH and OD fragments of the two-photon dissociation of H₂O and D₂O at 266 nm is reported. Values of the alignment parameter A₀⁽²⁾ are found to be close to zero, independent of rotational level, in contrast to single-photon dissociation studies at slightly higher energies. The rotational energy distribution in OH(A ²Σ⁺) is very similar to those reported for single-photon dissociation. Laser-induced fluorescence of OH(X²Π) was observed, but was shown to arise from collisional processes and not from direct photolysis.