Microelectromechanical deformable mirrors

摘要

A new class of silicon-based deformable mirrors is described.nThese devices are capable of correcting time-varying aberrations innimaging or beam forming applications. Each mirror is composed of anflexible silicon membrane supported by an underlying array ofnelectrostatic parallel plate actuators. All structural and electronicnelements were fabricated through conventional surface micromachiningnusing polycrystalline silicon thin films. A layout and fabricationndesign strategy for reducing nonplanar topography in multilayernmicromachining was developed and used to achieve nearly flat membranensurfaces. Several deformable mirrors were characterized for theirnelectromechanical performance. Real-time correction of opticalnaberrations was demonstrated using a single mirror segment connected tona closed-loop feedback control system. Undesirable mirror contoursncaused by residual stress gradients in the membrane were observed