Optical efficiency of MEMS deformable mirror for adaptive optics

Abstract

MEMS deformable mirror (DM) has yet to be incorporated into a facility AO instrument especially for atmospheric compensation. Apart from these drawbacks such as limited stroke, reliability, its optical efficiency should also be concerted. The wavefront corrector in AO system should existing high optical efficiency especially atmospheric compensation under faint stars. However the MEMS DM fabricated by surface process must have etch holes in the surface of mirror. The diffraction results from etch holes decrease its optical efficiency. An MEMS deformable mirror is fabricated by commercial PolyMUMPs. There is array of etch holes to ensure that the sacrifice layer is released fully. The far field intensity distribution was simulated. The result has been analyzed and used to constructed a simple modal of the studied MEMS DM.