Piezoelectric deformable mirror with adaptive multiplexing control

Abstract

We describe a simple and efficient implementation of adaptive multiplexing control for high-order piezoelectric deformable mirrors. The relatively high capacitance of piezoelectric actuators allows the electrical charge to be stored in a disconnected actuator, retaining its displacement while the other actuators can be addressed. Adaptive multiplexing, consisting of selective addressing of only those actuators that need to change their elongation in the current cycle, improves the mirror performance and simplifies the driver electronics. In experiment, a 12-channel prototype of a deformable mirror with multiplexing control has been characterized. At appropriate update rates with a fixed set of control signals, the shape of the deformable mirror remains nearly constant. A surface displacement error does not exceed ~ /100 rms at a multiplexing frequency of 700 Hz with a full interactuator stroke of ~2 µm.