Shape Control of an Adaptive Mirror at Different Angles of Inclination

The topic of this paper is the quasi-static shape control of an adaptive mirror, which is deformed due to gravity at different angles of inclination. Next to the basic design aspects of the adaptive mirror, a comparison between the numerical and experimental results is presented. Special emphasis is given to the description of the experimental setup for the verification of the shape control. Since for this structure the gravity-induced deformations are in the order of micrometers, a speckle interferometric measurement system and phase-shifting techniques have been used. The experimental data obtained with respect to the out-of-plane displacement of the mirror confirm the results of the numerical simulations. Moreover, the efficiency of the shape control is investigated and a correction scheme is presented.