A Low Voltage, 256 Electrode Membrane Mirror System for Adaptive Optics

Low stress membrane mirrors will allow improved wave front correction in vision science and astronomical adaptive optics systems. We have fabricated low stress membrane mirrors from single crystal silicon, and flip chip bonded membranes to electrode arrays. These devices operate at lower voltage and have greater stroke than existing membrane mirror devices; they have 256 control electrodes, and are driven by off chip electronics. Devices have a single electrode plane and are pre-biased to allow full wave front correction. We have demonstrated these devices in an adaptive optics system consisting of a coherent source, and a Shack-Hartmann wave front sensor. We compare the experimental performance of the devices to computer simulations and theoretical calculations.