Two-axis electromagnetic fast steering MEMS micromirror with a 10-mm-large aperture for satellite communications

Microelectromechanical system (MEMS) technology has been exploited to miniaturize fast steering mirrors (FSMs) for free space laser communications between satellites. However, fast steering MEMS mirrors (FSMMs) face tradeoffs among the optical aperture, mirror flatness, maximum steering angle, and response speed. To address this issue, this work has developed a novel electromagnetically driven FSMM that has a large optical aperture of 10 mm, a mirror radius of curvature of 64 m, a maximum steering angle of 15.3 mrad, and Q values of 26 and 46 for the fast and slow axes, respectively. These characteristics can match conventional FSMs but with a size reduction of at least one order of magnitude. This FSMM's high performance is achieved by employing an all-single-crystal-silicon microstructure, integration of 0.5 mm-thick miniature NdFeB magnets with high remanence up to 14.7 kGs at the edge of the mirror plate, and micromachined copper coils. Such an FSMM weighs only 0.9 g, providing a promising solution for satellite optical communications.