A High-Speed Large-Range Tip-Tilt-Piston Micromirror Array

This paper introduces the design of a high fill-factor (>99%) micromirror array that consists of 1 mm
²
hexagonal mirrors, which are expected to each independently achieve continuous, closed-loop control of three degrees of freedom (DOFs)-tip, tilt, and piston-over large ranges (> ± 10° rotation and > ± 30μm translation) at high speeds (~45 kHz for a 1° amplitude of rotational oscillation). The flexure topology of this array is designed using the freedom, actuation, and constraint topologies synthesis approach, which utilizes geometric shapes to help designers rapidly consider every flexure topology that best achieves a desired set of DOFs driven by decoupled actuators. The geometry of this array's comb-drive actuators is optimized in conjunction with the geometry of the system's flexures using a novel approach. The analytical models underlying this approach are verified using finite-element analysis and validated using experimental data. The capabilities of this new mirror array will enable, or significantly improve, the performance of a variety of high-impact optical technologies such as advanced optical switches, spatial-light modulators, displays, and laser steering or scanning devices.