Novel technology and performance of a high-power CO2 waveguide laser

Several new techniques have been developed to solve the problems encountered in the design and construction of rugged, reliable, high-power, CO₂ waveguide lasers. High-power single transverse mode output requires long single- or multiple-folded waveguide paths to be created in a dense ceramic body. The limitations of extruded or drilled bores have been overcome by fabricating the waveguide in two halves which are subsequently bonded together with a glaze or by thermodiffusion to form a vacuum-tight assembly. Several lasers have been constructed by these methods, one such device giving over 10 W CW output is described. These techniques can be readily extended to larger, higher-power devices. Reliable seals between semiconductor optics and metals using pure In soldering have also been developed for clean “hard seal” assembly. Dissociation of the CO₂ gas can lead to rapid decline in output power. The effects can be reduced by attaching a reservoir to the laser, or more preferably by the incorporation of a catalyst to reverse the reaction. These techniques have been applied to sealed-off CO₂ waveguide lasers which have demonstrated 5 yr shelf life and up to 5000 h operating life.