Testing of thermally piezoelectric deformable mirror with buried functionality

Abstract

Laser-induced mirror deformation and thermal lensing in optical high power systems shall be compensated by a thermally-piezoelectric deformable mirror (DM). In our device, the laser-induced thermal lensing is compensated by heating of the DM as previously described with compound loading. We experimentally show the capability of this mirror for wavefront shaping of up to 6.2 kW laser power and power densities of 2 kW/cm2. The laser-induced defocussing of the membrane is compensated by mirror heating. We introduce a new mirror setup with buried heater and temperature sensor elements. Therewith, the compensation of laser-induced mirror deformation is possible within the same time scale. The piezoelectric stroke of the single actuators depends on their position on the membrane, and is not affected by the reflected laser power.