Eliminating High-Spatial-Frequency Topography Due to Print-Through in MEMS Deformable Mirrors

This proposal aims to make fundamental progress in one of NASArsquo;s core objectives: to explore Earth-like exo-planets using space-based Coronagraphs. Coronagraphs null starlight speckles using deformable mirrors, enabling planet detection. One NASA-identified technology gap is the need for compact, ultraprecise, multi-thousand actuator deformable mirrors (DMs). Boston Micromachines Corporation is a leading producer of such DMs, which have been used in space-based applications and NASA Coronagraph test beds. However, their surface quality is currently limited to ~10nm-rms by topographic print-through on the mirror surface. BMC proposes to employ a modified manufacturing process developed in Phase I research tonbsp;eliminatenbsp;print-through. The new process will lead to production of DMs with surface figure errors measuring 1nm-rms. Such DMs are needed for all space-based coronographs that have been proposed for future NASA missions including WFIRST, HabEx, and LUVOIR