Two-photon photochemistry: Angular distribution of photofragments and application to isotope separation

The resonant two-photon dissociation process in a supersonic molecular beam is investigated. Angular distributions of photofragments in such a process are derived via a density matrix formalism. Conservation of angular momentum and bound-continuum Franck--Condon factors determine the angular distributions and the photodissociation cross sections. Criteria which the polarization state of the photon fields and the initial J state of the molecule should meet, to have the largest cross section and good photofragment collection efficiency, are discussed. Applications are foreseen in laser isotope separation