High Resolution Silicon Deformable Mirrors

This proposal describes a plan to build a prototype small stroke, high precision deformable mirror suitable for space-based operation in systems for high-resolution imaging. The prototype DM will be fabricated through a novel combination of micromachining and wafer bonding steps, and will rely on single crystal silicon for all structural components, promising unprecedented thermal stability and optical quality. These DMs will have a 65 mm aperture diameter, 4096 of degrees of freedom, 1?m of stroke, and a highly reflective mirror surface that can be adjusted repeatably to within 1nm RMS over the controllable range of spatial frequencies. The device will address all fundamental requirements for DMs to be used in space-based applications, by combining the best features of conventional discretely-assembled macroscale DMs (e.g. large aperture, good optical quality, and high reliability) with the best features of integrated microelectromechanical system (MEMS) DMs fabricated using semiconductor processing techniques (e.g. nanometer-scale repeatability, scalability to >104 actuators, and compactness). By using the full area of a silicon wafer for each mirror, these MEMS DMs will be significantly larger than any previously-reported MEMS DM. The device architecture will parallel that of the highly successful commercial MEMS DMs that were pioneered by Boston Micromachines Corporation.