Series operation of direct current xenon chloride excimer sources

Stable, direct current microhollow cathode discharges in mixtures of hydroc hloric acid, hydrogen, xenon, and neon have been generated in a pressure ra nge of 200-1150 Torr. The cathode hole diameter was 250 mu m. Sustaining vo ltages range from 180 to 250 V at current levels of up to 5 mA. The dischar ges are strong sources of xenon chloride excimer emission at a wavelength o f 308 nm. Internal efficiencies of approximately 3% have been reached at a pressure of 1050 Torr. The spectral radiant power at this pressure was meas ured as 5 mW/nm at 308 nm for a 3 mA discharge. By using a sandwich electro de configuration, consisting of five perforated, alternate layers of metal and dielectric, a tandem discharge-two discharges in series-could be genera ted. For an anode-cathode-anode configuration the excimer irradiance, recor ded on the axis of the discharge, was twice as large as that of a single di scharge. The extension of this basic tandem electrode structure to a multip le electrode configuration allows the generation of high irradiance excimer sources. Placing such a structure with a string of microhollow cathode dis charge into an optical resonator promises to lead to a direct current micro excimer laser. (C) 2000 American Institute of Physics. [S0021-8979(00)07018 -3].