Amplifying medium behavior of an AC-excited high-power CO2 laser

In order to achieve a compact industrial fast axial flow CO2 laser delivering an output power of a few kilowatts with a high beam quality, the authors have investigated the behavior of an amplifying medium excited by an ac discharge also called `silent discharge.' The external electrodes discharge tube and this ac power supply have been developed. The power supply was working in a resonant mode within a frequency range of 95 kHz to 125 kHz and showed that the power transmitted to the load can be modulated by frequency modulation. The dependence of the capacitive coupling between the power source and the discharge load on the electrode geometry are studied. The dependence of the gas temperature on the electrical characteristics of the source such as voltage, current, phase, and injected power are displayed. In this paper we show that for a gas temperature of 200 degree(s)C the maximum input power density was limited to 11 W/cm3. In an attempt at a laser application, an efficiency of over 15% was obtained with a laser output power of 800 W for an electric power of 4,800 W.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.