Neue physikalische Wirkprinzipien bei Hochleistungs-Gaslasern. Stroemungsgekuehlte und diffusionsgekuehlte CO_2-Laser mit Strahlleistungen > 5 kW Abschlussbericht

In the power range between 1 kW and 10 kW the world market for industrial laser materials processing has been dominated by fast flow CO_2 lasers either rf excited or dc excited. This research project deals with two different solutions which both promise fundamental progress with respect to today's available technology. The principal objective of the first part of this project has been to increase the total output power of radiofrequency excited slab waveguide CO_2 lasers. This goal has been realised in three steps. For a single module slab, the maximum output power has been increased to 3.3 kW by improvements of the rf matching and of the waveguide characteristics. The size of a single module was optimised and a double module slab has been built. The maximum output power achieved has been 4.2 kW and was limited by the rf generator. In the second part of the project, the general potential of high frequency discharge excitation in the 100 kHz range has been investigated. A discharge test stand was developed consisting of a discharge chamber, a closed-loop gas ciruclation system and a transistorised switched mode power supply. A maximum input power of 16.5 W/cm"3 was achieved. It has been shown that this excitation method may have several advantages compared with the conventional dc excitation and rf excitation. (orig.)SIGLEAvailable from TIB Hannover: F99B610+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman