Extended range tuning elements for a microelectromechanical systems external cavity laser

Abstract

A modified tuning element for a Littrow external cavity laser is demonstrated using microelectromechanical systems technology. The device combines a vertically etched blazed grating, a compound flexure suspension and drive elements for translating and rotating the grating. Tuning is linearized by linking the grating to a remote actuator by a flexible linkage. A simple theoretical model of the linkage is presented. Devices with electrostatic and electrothermal drives are both demonstrated by deep reactive etching of bonded silicon on insulator, and used to construct electrically tunable lasers. Prototypes show improved electromechanical characteristics and tuning over a range of 8 nm is demonstrated.

A dual-side fabrication method for silicon plate springs with high out-of-plane stiffness

“…With the silicon-based miniaturization of sensors and actuators, the use of flexible guiding mechanisms has been extended to the silicon micro domain. Many examples of micro systems based on plate springs, or comparable flexible joints, can be found in literature, for instance a gyroscope [1], an optical switch [2], a tuning element for an external cavity laser [3], an electro-thermal micromotor [4], a microactuator for hard disk drives [5], and a positioning stage for high resolution microscopy [6]. For these examples it is important to constrain undesired motion directions with high stiffness, for instance to avoid cross-talk in a gyroscope or to prevent alignment errors in an optical switch.…”