Single Crystal Actuators for Deformable Membrane Mirrors

Single crystal piezoelectric actuators are proposed as a means of increasing actuator authority while maintaining strain precision for adaptive optics mirrors used in directed energy applications. These materials exhibit 5 to 10 times the strain ofconventional ceramic piezoelectrics with equivalent deliverable force. Therefore, they offer a much broader design space for adaptive optics systems than is currently available with ceramic actuators, electric motors or magnetic devices. For the proposedprogram TRS Technologies will team with SRS Technologies to develop a variety of single crystal actuators for adaptive optics deformable mirrors. TRS will measure the performance of both stack and low-profile plate-type actuators, and SRS will model theimpact of incorporating such actuators into state-of-the-art deformable mirror designs such those incorporating piston-type actuator arrays or edge control. Crystal actuators will offer either greatly improved authority (5X greater displacement atequivalent or greater force than conventional systems) or much smaller size (5X weight reduction) with performance equivalent to electrostrictive PMN ceramic actuator arrays. In addition, single crystals can yield these performance improvements without aloss in precision relative to ceramic PMN, and they are capable of operating over a much broader temperature range. Single crystal piezoelectrics will greatly advance the use of deformable mirrors in a broad variety of military and other governmentapplications including directed energy systems, airborne and space based communications systems, and space based telescopes. In addition membrane mirrors also have applications in such broad range of commercial markets such as laser scanners, de-focuscorrection, wavefront corrector, precise pellicles, imaging auto-focus optics, technical vision, and ophthalmology.