Continuously deformable mirrors

Low spatial and temporal frequency correction of optical wavefronts can be achieved with continuously deformable mirrors that are being developed by the Atomic Vapor Laser Isotope Separation (AVLIS) Program at Lawrence Livermore National Laboratory. These devices are simple in design, low in cost, require relatively few actuators, and are capable of submicron deformation control using conventional stepper motors. The technique involves bending a mirror substrate with actuators that apply variable bending moments typically around the perimeter of the mirror. The location and orientation of these actuators and the thickness variation of the substrate determine the particular static shape that will be generated and the optical distortion that it can correct. For constant-thickness substrates the deformation will generally follow a curve that can be described by a quadratic function. However, by contouring the back surface of the substrate, higher-order deformations can be generated. Among the optical aberrations that can be generated by this technique are focus, astigmatism, coma, and spherical aberration. More complex shapes and other applications are being investigated. This method may also be useful in the manufacturing of aspherical optics