Exchange chemical lasers for the visible and near-infrared ranges utilizing electronic transitions in halogens and interhalogen compounds

An analysis is made of the principal thermodynamic, spectroscopic, kinetic, and radiative characteristics of halogen and interhalogen compound molecules as active media in chemical lasers, and of corresponding quasiresonant donor partners in the form of metastable radicals. The chemical processes generating electronically excited donor particles, including a new class of reactions involving alkali metal atoms, are given. Specific, most promising donor–acceptor pairs are identified. Estimates are obtained of the threshold density of the population inversion needed for lasing. A systematic analysis is made of the processes of formation of electronically excited I(²P_1/2) iodine atoms and O₂(a¹Δ) oxygen molecules which are of interest as auxiliary donors. Several kinetic schemes for initiation of pulsed NF–IF lasers are discussed. A specific scheme for a NF–I₂ chemical laser emitting in the visible range is proposed.