Optical inhomogeneities of the active media of high-power industrial CO2 lasers with fast axial flow

Theoretical and experimental investigations showed that a diverging thermal gas lens, which forms in high-power industrial lasers with fast axial flow of the active medium, can influence the diffraction losses in the laser oscillator and the beam parameters. The nonlinear optical properties of the lens, demonstrated by the dependence of its optical power on the intensity of the output radiation, are described.