A VERSATILE MICROWAVE PLASMA SOURCE AND ITS APPLICATION FOR A CO2-LASER

A single ridged waveguide with nonconstant ridge height, operated with a traveling wave has been proven to be a versatile microwave plasma a pplicator. Easy dimensioning, inexpensive production, and compatibilit y to standard rectangular waveguide components are the main advantages compared to other designs. The described plasma source is especially suitable for any applications where an exceptionally uniform plasma is required. Design equations are given for easy adaption of the applica tor to individual requirements. The applicator has been investigated f or microwave excitation of a diffusion-cooled CO2 laser. With a nonopt imized system, laser output power of 9 W could be achieved in a quasi- cw mode. A traveling discharge operating mode is described which is us eful for plasma diagnostics and for pulsed laser applications.