Gain of a CO2 waveguide laser

An analytic expression is obtained for the unsaturated gain of the active medium in a CO₂ waveguide laser. A calculation is reported of the gain in a CO₂:N₂:He= 1:1:8 mixture. The dependence of the gain on the pressure in the active medium and on the laser tube diameter is obtained for different pump currents. The role of various mechanisms of the relaxation of excited molecules in the plasma of a CO₂ waveguide laser is considered.