Optical losses in CO-GDL accompanying resonant self-absorption of the induced radiation

Abstract

The radiation spectrum of the gasdynamic laser is examined and the change in the absorption coefficient of the medium accompanying the action of resonance radiation on the upper vibrational levels of the molecules is illustrated. The distribution of the absorption coefficient for the radiation of a gasdynamic CO laser over vibrational levels at 1300 K, total density of the radiation flux being 250 W/cm/sup 2/ at various times, is shown. It is shown that additional channels for optical losses, associated with the appearance of self-absorption of part of the energy of the optical radiation by regions of thermalized gas, accompanied by a decrease in the efficiency of the laser resonator owing to a drop in the integrated gain of the medium as well as by a shift of the caustic and misalignment of the resonator accompanying the appearance of transverse density gradients of the flux in the absorbing regions, can arise in the laser.