Influence of the cavity losses on the energy and spectral characteristics of a pulsed chemical chain-reaction HF (DF) laser

The dependences of the energy and spectral characteristics of the radiation of a pulsed photoinitiated chemical chain-reaction HF (DF) laser, operating at atmospheric pressure, on the optical cavity parameters were investigated. The maximum specific output energies of the HF and DF chain lasers (53 and 43 J litre^-1) and their fullest spectra (47 and 83 lines, respectively) were similar when the unsaturated gain exceeded the threshold by a factor greater than 50. An analysis was made of how the energy and spectrum of the radiation of the HF (DF) laser were influenced by the spatiotemporal inhomogeneity of the initiation and of the course of the chemical chain reaction. There was a marked effect of the CO₂ molecules in the active medium and in the air filling part of the volume of the complex cavity of the DF laser on its efficiency and emission spectrum.