Small-scale optical inhomogeneities in electron-beam-controlled СО2 lasers

The concept of stimulated enthalpy scattering is combined with an allowance for a finite aperture in an analysis of the growth of small-scale optical inhomogeneities oriented along the optic axis of a plane–plane resonator of a CO₂ laser. In the limit of high values of the Fresnel number N_F, an analysis of the branching points of the dispersion equation for these inhomogeneities is tackled by a singular theory of perturbations in terms of N_F ^– 1. This analysis shows that small-scale optical inhomogeneities are mainly due to the scattering by acoustic modes.