Photo controlled deformable mirrors: materials choice and device modeling

Abstract

Photo Controlled Deformable Mirrors (PCDMs) are electrostatic membrane mirrors where a photoconductive material replaces the conventional electrode pads, so that the mirror surface deforms according to a light pattern projected on the photoconductor, leading to a simplified control system. A proper device design and manufacturing has to take into account many different issues and the material choice is of primary importance. After a brief description of PCDM working principles we consider an equivalent electrical model, deriving the photoconductor's parameters that most influence the device performances and show some examples among currently available photoconductors. Finally, we propose a complete electro-opto-mechanical model that allows to optimize the system and to enhance the mirror performances.