Tunable blazed gratings

In this paper, we report on the design, fabrication, and characterization of blazed gratings made tunable by electrostatic actuation. We combine KOH etching and deep-reactive ion etching (DRIE) to fabricate tunable blazed gratings (TBGs) on silicon-on-insulator wafers with optical-quality mirror surfaces on {111} crystalline planes. The actuators that are used to position the individual grating elements are designed to reduce rotation to levels acceptable for spectroscopic applications. We characterize the fabricated devices mechanically, verify the rotation-reduction design, and demunstrate the functionality of TBGs as tunable filters. [1552] Index Terms--KOH etching, microelectromechanical systems (MEMS), optical filter, optical grating, optical microelectromechanical systems (MEMS).