New type of microwave excitation structure for gas laser

Summary form only given, as follows. Despite the fact that microwave discharges have many benefits for exciting gas lasers, considerable problems in exciting an extended, homogeneous plasma volume at high gas pressures and sufficiently low gas temperatures prevented the breakthrough of microwave excitation for some time. Without an appropriate microwave discharge structure, the high critical power density and skin effect, result in non-homogeneous, overheated discharges burning, and the dissociation of working gases. We introduce a new type discharge structure-waveguide coupled cavity for microwave excitation of gas lasers, which allows us to overcome the problems mentioned above. The design principle of the cavity is described through its low frequency equivalent circuit. Without the ignition bar, this cavity has the characteristics of a simple structure and low discharge breakdown power, experimental results show that the cavity can simultaneously realize frequency tuning resonant discharge and impedance matching. The relationship between the plasma intense luminescence and discharge parameters is also discussed in this paper.