The optical quality of a pulsed atmospheric CO2 electric laser is investigated. The density disturbances in the optical cavity are caused by edge waves originating at the anode and cathode. Volumetric heating effects associated with a nonuniform electric discharge are shown to be negligible. The disturbance propagating from the cathode results from a discontinuity in the spatial heating and the cathode fall. The wave emanating from the anode is associated with the presence of a solid surface that prevents the gas from expanding. As a result, lasers have to be designed with pulse durations much less than the acoustic transit time across the cavity.
E. R. Pugh, J. Wallace, J. H. Jacob, D. B. Northam, and J. D. Daugherty, "Optical Quality of Pulsed Electron-Beam Sustained Lasers," Appl. Opt. 13, 2512-2517 (1974)