Piezo actuators for telescope active optics

Piezo actuators are commonly used within Fast Steering Mirrors (FSM) for active stabilization, pointing and tracking functions. Such compact mechanisms are requested for Free-Space Optics and Deep Space Optical Communication since they are embedded and offer fast (up to 1kHz) and precise (µRad) tip tilt motion (up to +/-2°). The use of large amplified actuator within mirror telescope is new and become relevant since it displays enough power, reliability and do not fall apart when a failure occurs: steady state design with high stiffness 64N/µm. The purpose of this paper is to present the development and the qualification of the world largest Amplified Piezo Actuator ever integrated in a telescope tip-tilt mirror of more than 2 meters diameter.