Preliminary characterization of Boston Micromachines' 4096-actuator deformable mirror

We present preliminary findings on the characteristic behavior and initial performance of Boston Micromachine Corporations' (BMC) 4096-actuator micro-electrical mechanical systems (MEMS) deformable mirror (DM). This device is examined for its application in the Gemini Planet Imager high-contrast adaptive optics (AO) system. It is also being considered for use in next generation AO systems on the extremely large telescopes. Testing of this device has been in progress at the Laboratory for Adaptive Optics (LAO) on the Extreme Adaptive Optics (ExAO) testbed in experiments designed to qualify performance for imaging extrasolar planets. In this paper we present first test results including actuator stroke (3.0 microns at 200 V), individual actuator RMS surface (10.3 nm surface), actuator yield for two DM arrays (94.4% and 98.8%), actuator crosstalk (no more than 32%), stroke at the highest spatial frequency (1.2 nm surface), and sub-nanometer closed loop flattening capabilities over a 30-actuator diameter.