Turbulent structure of the active medium of a fast-flow CO2 laser

The characteristics of turbulent pulsations of the gas density and velocity and the structural characteristic of fluctuations of the refractive index C_n² in the gaseous-mixture flow of a fast-axial-flow CO₂ laser are determined using optical diagnostic methods: the luminescence, interferometry, and degenerate four-wave mixing techniques. The influence of a gas discharge and lasing on turbulent small-scale optical inhomogeneities of the active medium is investigated. It is shown that, in the presence of a gas discharge and laser oscillation, the inhomogeneities appreciably increase due to nonlinear effects of a local heat release in the thermodynamically nonequilibrium turbulent gaseous medium.