Adaptive thermal optics in high-power laser resonators

In order to compensate for the thermally induced lenses in high-power laser rods we investigate self-adaptive techniques based on thermo-optical processes. Recently we have demonstrated that the influence of the thermal lense in high-power lasers can be reduced significantly by means of a thin liquid layer located within the resonator. Here we report on the investigations of different liquids and gels for the generation of the adaptive lens and discus an improved implementation of the technique, with the compensating layer placed directly in contact with the laser rod.