Non-contact Deformable Mirror Actuator for Spherical Aberration Compensation

Abstract

We have proposed and demonstrated a novel non-contact electromagnetic deformable mirror actuator for spherical aberration compensation with simple configurations. The magnetic ring with low stiffness placed on a mirror deformed the mirror into an ideal parabolic shape by applying a magnetic force generated from an electromagnet underneath. We were able to control the deformation of the mirror by adjusting the applied voltage. The maximum deviation from ideal shape was less than 30 nm. In addition, a continuous change of the defocus aberration proportional to the 1.5-RMS /m deformation of the mirror was achieved. #

Design of novel deformable mirror with large displacement

“…However, the bimorph piezoelectric DM is only suitable for low‐order deformation due to much fewer actuators 38,39 . MEMS DM is only suitable for small size, low cost, and fast response applications, and the displacement is no more than 10 μm 40–42 …”

“…38,39 MEMS DM is only suitable for small size, low cost, and fast response applications, and the displacement is no more than 10 μm. [40][41][42] A stabilized zoom system was desired for a zoom system with fast imaging of distant targets. The traditional piezoelectrically-actuated deformable mirror (PADM) has been unable to meet the requirements [43][44][45] for this system because the larger displacement leads to severe mirror stress, 46 which affects the fitting accuracy of the DM 47,48 and may even damage the mirror.…”