Similarity and scaling in diffusion-cooled RF-excited carbon dioxide lasers

The theoretical and experimental study of alpha RF discharges presented in this paper has resulted in the formulation of a set of similarity and scaling laws for diffusion-cooled alpha RF discharge-excited CW waveguide CO₂ lasers. For the first time, the parametric dependencies of the voltage-current-power characteristics of transverse alpha RF discharge have been investigated over a range of excitation frequencies 100-160 MHz, for gas pressures 40-100 torr and for interelectrode distances 1-3 mm in a typical waveguide CO₂ laser gas mixture (He:N₂Co₂ = 3:1:1+5 percent Xe). Relative to dc discharges, the additional scaling law fD = constant is established, and the analysis indicates both high- and low-frequency limits to the operation of practical self-similar laser devices.