Performance of a woofer-tweeter deformable mirror control architecture for high-bandwidth high-spatial resolution adaptive optics

Abstract

To compensate for large phase errors at high bandwidth, a dual deformable mirror (DM) architecture is introduced. One DM (the tweeter) handles the high spatial resolution errors with a small stroke, high bandwidth, capability while the other DM (the woofer) corrects the larger but more slowly varying phase errors with a larger stroke capability. An offload control architecture is shown to be very effective with the Kolmogorov turbulence spectrum. The architecture is also shown to be effective when used with a self-referencing interferomenter (SRI) wavefront sensor and an exponential control law for phase unwrapping. Performance is verified in simulation and in an advanced wavefront control testbed facility at the Air Force Research Laboratory.