Optically driven microelectromechanical-system deformable mirror under high-frequency AC bias

Abstract

A new, optically addressed deformable mirror device is demonstrated. The device consists of a pixellated metalized polymeric membrane mirror supported above an optically addressed photoconductive substrate. A conductive transparent ZnO layer is deposited on the back side of the substrate. A very high-frequency AC bias is applied between the membrane and the back electrode of the device. The membrane is deformed when the back of the device is illuminated because of impedance and bias redistribution between two cascaded impedances. We fabricated, demonstrated, and modeled the operation of this device.

Optically addressable deformable membrane mirror

“…Recently, an optically driven membrane mirror has been realized for near infrared applications, where the addressing was through a photoconductive substrate, nevertheless the membrane and the associated driving were pixellated [6][7][8] , whereas in our case the photo-addressing is continuous. The device is schematically represented in Fig.1.…”

High resolution wavefront correction with photocontrolled deformable mirror

“…The PCDM is an electrostatic membrane deformable mirror [20,21], where the electrode pads, used conventionally in membrane mirror devices, have been replaced by a photoconductive crystal [13,15]. Among available photoconductors (for instance, Silicon or Gallium Arsenide [19]), we have used a Bismuth Silicon Oxide (BSO) crystal because it has the advantage of presenting a low absorption coefficient, which allows a large penetration depth, and of being characterized by a capacitance similar to the one formed by the membrane, thus, allowing for a large modulation of the voltage drop across the membrane mirror.…”

“…Although a few prototypes of PCDM have already been reported in literature [13,19], their capability in terms of high spatial resolution and their use in an adaptive optics setup have not been explored yet. The aim of this paper is to demonstrate the PCDM capability in providing high performance adaptive optics implementations.…”