Options
1995
Conference Paper
Titel
Optimization of power incoupling and statistical phase distortions by flow shaping of fast axial flow CO2 lasers
Abstract
In the development of fast axial flow (FAF) high power CO2 lasers the increase of mass flow and the reduction of phase distortions are of main interest in the realisation of high output power with high beam quality. Both topics strongly depend on the layout of the flow system for the convective cooling of the medium. Reducing the pressure losses in the closed loop gas circuit guarantees an enhanced mass flow in the system. The element at the outlet of the discharge tubes is the place of the largest pressure losses in FAF CO2 lasers. Optimized geometries have been developed to increase the mass flow significantly. The inlet into the discharge tube is of major interest due to phase distortions of the active medium. Besides stationary, statistical phase distortions strongly influence the output power and beam quality. The influence of inlet geometries on the flow profile has been investigated. The discharge stability could be clearly improved by new developed geometries. Measurements of s tatistical phase distortions under different flow and discharge conditions have been obtained. The work on optimizing the geometries enabled the enhancement of power incoupling into the discharge with an simultaneous decrease in the statistical phase distortions. Experimental results are presented.