Theoretical and experimental investigations of the filamentation of high-frequency excited CO2 laser discharges

The filamentation of high-frequency excited C0sub2 laser discharges with dielectric electrodes is investigated theoretically and experimentally. A self- consistent two-dimensional discharge model including equations for the electron density, the electric field and the neutral gas density is used to calculate the spatiotemporal development of filaments in a high- frequency discharge. The space charge field is described implicitly by the complex dielectric constant of the discharge plasma. The side-or light emission of high-frequency excited discharges is recorded, time-integrated by a camera and time- resolved by using a framing camera. Filaments develop above a critical value of the power density which depends on the pressure. The development of the filaments is partly suppressed by the dielectric electrodes.