Adaptive optics with a thermally activated mirror for the correction of phase front disturbances in high-power laser systems

Abstract

In a solid state laser system high pump powers can result in strong temperature gradients affecting the phase front of the beam due to deformation and locally varying refractive indices in the active medium. A dynamic correction process is desirable in order to compensate distortions at different pumping powers. Here we present an adaptive optics (AO) system applicable to high power beams. Main component of the system is a mirror that consists of a colored glass absorbing below 900 nm and a coating which is highly reflective above 950 nm. It can be heated and deformed by the intensity distribution of an 808 nm beam that has been modulated via a DMD. The resolving capacities of the AO have been analyzed and measures taken to improve them. In the next step, the performance of the AO correcting an incoming wave modified with defined distortions will be investigated. In future, the system will be implemented into a thin-disk amplifier to compensate phase aberrations of the active medium. The current status of the project is presented.