Open-loop performance of a high dynamic range reflective wavefront sensor

Sandia National Laboratory has constructed segmented Micro-Electro-Mechanical deformable mirrors that are under investigation for their suitability in experimental Adaptive Optics systems for the Naval Research Laboratory. These mirrors are fabricated in a hexagonal array and can been constructed with flat surfaces, or with optical power allowing each mirror to bring its subaperture of light to a focus similar to a Shack-Hartman array. Each mirror can use the tip, tilt and piston function to move the focused spots to the reference location, and the measurement of the applied voltage can be used directly to power a similar flat MEMS deformable mirror. Unlike the Shack-Hartman array, this wavefront sensor can detect large magnitude aberrations up to and beyond where the focused spots overlap, due to the ability to dither each focused spot. Previous publications reported on this novel new technique and the electrical specifications, while this paper reports on experiments and analysis of the open-loop performance, including repeatability and linearity measurements. 1 Naval Research Laboratory Remote Sensing Division, Code 7216 3550 Aberdeen Ave SE Kirtland AFB, NM 87117 2 New Mexico Institute of Mining and Technology Electrical Engineering Department 801 Leroy Place Socorro, NM 87801 3 Sandia National Labs 1515 Eubank Ave SE Albuquerque, NM 87123