Population and gain of a waveguide CO2 laser

A system of kinetic equations is solved for the population of the upper laser level of a waveguide CO₂ laser (or amplifier) having a cylindrical waveguide excited by a longitudinal electric discharge. A theoretical analysis is made of the dependence of the population and unsaturated gain of a waveguide CO₂ laser on the pressure and composition of the active mixture, pump current, and waveguide tube diameter.