Large aperture deformable mirror with a transferred single-crystal silicon membrane actuated using large-stroke PZT unimorph actuators

We have demonstrated a large aperture (50 mm /spl times/ 50 mm) continuous membrane deformable mirror (DM) with a large-stroke piezoelectric unimorph actuator array. The DM consists of a continuous, large aperture, silicon membrane "transferred" in its entirety onto a 20 /spl times/ 20 piezoelectric unimorph actuator array. A PZT unimorph actuator, 2.5 mm in diameter with optimized PZT/Si thickness and design showed a deflection of 5.7 /spl mu/m at 20 V. An assembled DM showed an operating frequency bandwidth of 30 kHz and influence function of approximately 30 %.