A discharge cell has been used to simulate conditions in fast flow, radio-frequency excited CO2 lasers using dielectric electrodes. The frequency dependence of the discharge structure and the Alpha to Gamma transition has been observed in the range 13 - 40MHz. The radio frequency, the thickness of the dielectric layer, and the parallel capacitance of the matching circuit are all shown to control the discharge uniformity and excitation conditions at the centre of the discharge.
Ignition voltages and pulsed and CW vector impedance measurements have been made for a fast axial flow RF excited CO2 laser, enabling quantitative design work on the RF power system. Comparisons are made between laser power control by analogue RF power and pulse modulation.