Piezoelectric unimorph MEMS deformable mirror for ultra-large telescopes

Abstract

This paper describes the results of our demonstration on a proof-of-concept piezoelectric unimorph-based deformable mirror (DM) with continuous single-crystal silicon membrane. A PZT unimorph actuator of 2.5 mm in diameter with optimized PZT/Si thickness and design showed a deflection of 5 μm at 50 V. DMs consisting of 10 μm thick single-crystal silicon membranes supported by 4×4 actuator arrays were fabricated and optically characterized. An assembled DM showed a stroke of 2.5 μm at 50 V with a resonant frequency of 42 kHz and influence function of approximately 25%.