Molecular frame properties from photodissociation of laboratory-oriented symmetric top and chiral molecules

Abstract

We review how molecular frame directional properties can be extracted from the photodissociation of laboratory-oriented molecules. Molecules can be hexapole state-selected and spatially oriented in the electric field of a velocity-map imaging lens. The oriented molecules are dissociated with the linear polarization set at a chosen angle to the orientation direction of the molecules. The angular distribution of photofragments is measured using the velocity-map imaging technique. From the observed asymmetry in the laboratory frame, we can directly extract the molecular frame angles between the final photofragment recoil velocity and the permanent dipole moment and the transition dipole moment. We discuss the photodissociation of oriented chiral molecules and show how the combination of laboratory orientation and selective laser excitation leads to a three-dimensional oriented, ‘fixed-in-space’, molecule in the excited state. From the recoil distribution in the laboratory frame, direct detailed molecular frame angular correlations can be extracted.