A Tip-Tilt-Piston Micromirror Array for Optical Phased Array Applications

• Published in: Journal of microelectromechanical systems 2010-12, Vol.19 (6), p.1450-1461
• Main Authors: Lei Wu, Dooley, Sarah, Watson, Edward A, McManamon, Paul F, Huikai Xie
• Format: Article
• Language: English
• Subjects: Actuation; Actuator design; Actuators; Applied sciences; Arrays; Circuit properties; Electric potential; Electric, optical and optoelectronic circuits; Electronics; Electrothermal bimorph; Exact sciences and technology; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Integrated optics. Optical fibers and wave guides; Mechanical instruments, equipment and techniques; microelectromechanical devices; Micromechanical devices and systems; Micromirrors; Optical and optoelectronic circuits; Optical arrays; optical phased array (OPA); Phased arrays; Physics; Pistons; Scanning; tip-tilt-piston (TTP) micromirror; Voltage
• ISSN: 1057-7157; 1941-0158
• DOI: 10.1109/JMEMS.2010.2076777

A tip-tilt-piston micromirror array based on electrothermal bimorph actuation is presented. The micromirror uses a compactly folded actuator design that can realize high fill-factor with a simple fabrication process. A 4 × 4 micromirror array with sub-apertures of 0.9 mm and a fill-factor of 54% is demonstrated. A piston actuation of about 200 μm and tip-tilt scanning of ±18° optical angles are obtained at a driving voltage as small as 4.5 Vdc. The mirror's tip-tilt steering capability and piston control make it promising for optical phased array applications. The phased array concept is demonstrated by phasing two adjacent mirrors on the mirror array. Other device characterizations including frequency, transient response, and mirror surface quality are also reported.