Novel Surface-Micromachined Micromirrors for Optical MEMS Beam Manipulators

A novel surface-micromachined electrostatic rotation micromirror is presented. The micromirror can be used to develop high performance optical beam steering manipulators for space applications based on an array of such micromirrors which are controlled by a feedback controller to compensate for jitter and misalignment during optical metrology or communication. The rotation micromirror has a two-layer structure and uses two repulsive force electrostatic actuators which generate a force to rotate the mirror out-of-plane. The rotation angle of the micromirror is not limited by the initial gap distance between the mirror plate and the substrate. By using repulsive force actuators, the surface-micromachined rotation micromirror can achieve a large rotation angle for a large mirror size without requiring any post-release assembly to fold the mirror out or raise it up. Prototypes fabricated using MUMPs are characterized by a mirror size of 312 μm × 312 μm, a stiffness of 0.485e−8Nm/rad, a mechanical rotation of 0° ∼ 2.2° at a driving voltage of 0 ∼ 200 V.