An experimental study of HF photodissociation: Spin–orbit branching ratio and infrared alignment

Abstract

Single rotational levels of HF (v=3) were prepared by using overtone excitation and these molecules were then photodissociated by ultraviolet (UV) radiation at 193.3 nm. Time-of-flight spectra of the hydrogen atom fragment provided the spin–orbit state distribution of the fluorine fragment. Changing the UV photolysis laser polarization confirmed an A 1Π←X 1Σ+ electronic transition in the photodissociation step. Photodissociation of HF at 121.6 nm is also reported. Infrared (IR) induced alignment of the diatom was studied by monitoring the IR laser polarization dependence of the H-atom product angular distribution. Depolarization due to hyperfine interaction was studied by using the R(0) transition. Agreement with theory is excellent.