Abstract

Transverse radio frequency (rf) gas discharges in the pressure and frequency ranges of respectively 10-150 Torr and 10-150 MHz are being increasingly used in free space and waveguide CO₂ lasers, at power levels from a few watts to kilowatts, because of a number of advantages rf excitation has over DC excitation. In the past decade rf excited waveguide CO₂ lasers were developed from all-ceramic channel structures to metal-ceramic channel and slab structures.¹ Recently, allmetal free space and waveguide structures for rf excited CO₂ lasers were presented, in which four walls of the channels were made from aluminium.^2,3 We proposed to research a new type of free-space and waveguide lasers in which the square cross-section structure of the discharge channels are formed only by two concave metal surfaces. The metal surfaces also become electrodes in rf discharge.⁴

© 1994 IEEE