50μm gap 8×8 pixels deformable mirror fabricated by membrane transfer process

Abstract

We propose, design and fabricate here an electrostatically actuated continuous single-crystal-silicon membrane deformable mirror (DM) for astronomical observation. A 50μm air gap is generated a large between the mirror membrane and the electrode to get a large stroke. A DM with a 4mm×4mm mirror membrane and 8×8 underlying electrode array a is fabricated by combining Au-Si eutectic wafer bonding and the subsequent all-dry release process.