Vibrational relaxation of excimers

A review of the vibrational relaxation of excimers is presented. Various kinetic models used in the literature to interpret experimental data and to model excimer lasers are discussed. Of these, those based on the Fokker—Planck diffusion equation are the most general due to the essentially nonequilibrium population of the hundreds of high vibrational levels and because of the multiquantum nature of the transitions involved. Numerous manifestations of these important kinetic features are analyzed. The diffusive relaxation concept has led to an overestimate of the influence of vibrational relaxation on excimer laser parameters, the saturant light flux and quantum yield expressions departing considerably from those commonly used. To gain insight into relaxation physics, considerable attention is given to the determination of kinetic parameters capable of adequately describing the electronic-vibration kinetics. Rate constants for excimer vibrational relaxation are also given.