Collisional and dissociative processes of the excitation of atoms and their role in lasing of alkali metal vapors

An investigation was made of the mechanisms of quenching of excited states and of excitation of atomic levels as a result of absorption of laser radiation by alkali metal (Na, K, Cs) vapors. It was found that several processes participated in the excitation of atomic levels: collisional mechanism of excitation energy transfer from molecules to atoms, photodissociation, predissociation, and nonresonant excitation of atomic levels (radiative collisions). The partial contribution of each of these processes (dependent on the vapor density, intensity of laser radiation, and its frequency) should be allowed for in the balance of the filling and deactivation of molecular and atomic states. Qualitative characteristics were obtained for these processes and an analysis was made of their likely role in the emission of radiation from diatomic molecules in alkali metal vapors.