Investigation of spatial characteristics of radiation emitted by an electron-beam-controlled CO2 laser with intracavity apodization

A study was made of the influence of smoothing of the edge of an exit mirror in an unstable resonator on the dynamics of the spatial structure of the radiation emitted by an electron-beam-controlled CO₂ laser. Numerical methods and experiments demonstrated that the self-interaction effects in the active medium of this laser were reduced by "amplitude smoothing" of the unstable resonator mirrors. Even when traditional working mixtures were used, the level of light-induced inhomogeneities in the active medium (and the divergence of the output radiation governed by these inhomogeneities) decreased strongly when "teeth" were formed along the perimeter of a metal exit window in the unstable resonator.