Thermal Balance and Active Damping of a Piezoelectric Deformable Mirror for Adaptive Optics

Abstract

Piezoelectric unimorph deformable mirrors offer a cheap solution to adaptive optics, with mass production capability. However, standard solutions have significant drawbacks: (i) the static shape is sensitive to the temperature, and (ii) the low structural damping limits the control bandwidth, because of the interaction between the shape control and the vibration modes of the mirror. This paper discusses how these two problems may be alleviated by using a mirror covered with an array of actuators working in d31 mode on the back side and a ring of transducers (actuators and sensors) on the front side, outside the pupil of the mirror.

Keywords

• piezoelectric
• unimorph
• bimorph
• deformable mirror
• adaptive optics
• thermal control
• active damping
• modal filters