THE EFFECT OF VOLTAGE PULSE POLARITY ON THE PERFORMANCE OF A SLIDING DISCHARGE PUMPED HF LASER

The influence of the applied voltage pulse polarity on the performance of a HF laser pumped by a sliding surface discharge is investigated. Details are presented for the polarity dependence of the discharge pro perties as well as for their relation to the physical processes that a ffect the sliding discharge evolution. The output energy and efficienc y were higher when the initiating or stressed electrode was in relativ e positive potential, irrespective of which electrode was grounded. Th e experimental results indicate that for positive polarity the dischar ge was more uniform, self terminating in type, with reduced electron d ensity and temperature. The increase in output energy and efficiency i s attributed to the improvement of the spatial uniformity of laser pum ping, to a more efficient utilization of discharge input energy due to an increase in the steady state discharge time phase, as well as to t he reduced electron temperature and to the increased steady state volt age which may also result in more efficient laser pumping.