Multiplexing Control of a Multichannel Piezoelectric Deformable Mirror

摘要

Addressing of massive arrays of piezoelectric actuators is usually achieved by using separate high-voltage output drivers, one per channel. This approach applied to high-order adaptive optics systems results in complex, expensive and vulnerable to handling abuse driver electronics, hardly scalable to 10~3-10~4 actuators. To reduce the number of identical electronic units and simplify the control, we propose sequential multiplexing of piezoelectric actuators. The relatively large capacitance inherent in mirror piezo-actuators allows for storage of charge (high voltage) on a disconnected actuator retaining its displacement, while other actuators are addressed. As a demonstrator a 12-channel piezoelectric deformable mirror driven by a single high-voltage amplifier has been characterized experimentally. The multiplexing of actuators was accomplished by miniature optical switches. Temporal stability of ～λ/100 was demonstrated at multiplexing frequency of 700 Hz with a full-range ～2 μm inter-actuator stroke. The developed approach can be scaled to higher-order deformable mirrors.