Abstract

Due to the fact that there is a need in the industry for compact and reliable laser sources with high beam power, the demands for efficiency and stability have to be input factors for the design process, as well as high output power and good beam quality. Hence a new coaxial CO₂ laser with fast axial gas flow, which satisfies all these requirements, has been developed and realised at the Technical University of Vienna in cooperation with an Austrian company. After two years of design and development, output powers up to 7 kW and diameters of the focused beam down to 300µm could be achieved with one single module. Besides the availability of new and improved mirrors and an ultra strong turboblower, the simplicity of this laser concept made it possible to build up a size-reduced and cost saving industrial laser device. However due to the high RF power input of 5^*10⁴ W in a small spatially limited coaxial discharge volume, a lot of mechanical, optical and thermodynamical investigations for the improvement of RF-matching, plasma performance and resonator stability have been necessary. In detail a very accurate thermodynamical analysis has been carried out. Numerical evaluation of the resonator has proved necessary to provide operation stability and satisfactory beam quality for industrial applications.

© 1996 IEEE