Adaptive surface shape control for magnetic fluid deformable mirrors

Adaptive Optics (AO) is a technology that can measure and correct the aberrated wavefront in real-time. A typical AO system mainly consists of a wavefront corrector, a wavefront sensor and a control unit connecting the former two to perform a correction based on information from the wavefront measuring device. Currently, the widespread used corrector is solid deformable mirrors. Compared to solid deformable mirrors, magnetic fluid deformable mirrors (MFDMs) are much cheaper and can offer larger stroke to correct large aberration. In this paper, a magnetic fluid deformable mirror is developed to be the wavefront corrector and a closed-loop adaptive control algorithm is adopted for the surface shape regulation. Simulation and experimental results illustrate the proposed adaptive method is able to regulate the surface shape at a desired value and against the unknown disturbances.