Design, construction and characterization of a fast axial flow continuous wave RF excited CO₂ laser

In this work, a continuous wave fast axial flow RF CO₂ laser has been constructed, which is pumped by a 1 kW RF generator with a 13.56 MHz frequency. In order to optimize the laser performance, the diameter of the discharge tube, electrodes width, the ratio of the width of the electrode to the tube perimeter, gas ratio, and total pressure of the gas mixture was changed over a wide range for a constant electrode length of 10 cm and then the laser output power and efficiency were measured. The maximum output power of 63.5 W, implying %6.3 electric efficiency, was obtained for 26 mm discharge tube diameter, electrode width to discharge tube perimeter ratio of 0.6, CO₂:N₂:He≡1:3:5 gas mixture, and 90 mbar total pressure.