Design and nonlinear servo control of MEMS mirrors and their performance in a large port-count optical switch

Author

Chu, Patrick B. ; Brener, Igal ; Pu, Chuan ; Shi-Sheng Lee ; Dadap, Jerry I. ; Park, Sangtae ; Bergman, Keren ; Bonadeo, Nicolas H. ; Chau, Tai ; Chou, Ming ; Doran, Robert A. ; Gibson, Rick ; Harel, Roey ; Johnson, John J. ; Lee, Shi-Sheng ; Peale, David

Author_Institution

Seagate Technol., Pittsburgh, PA, USA

Volume

14

Issue

2

fYear

2005

fDate

4/1/2005 12:00:00 AM

Firstpage

261

Lastpage

273

Abstract

In this paper, we demonstrate full closed-loop control of electrostatically actuated double-gimbaled MEMS mirrors and use them in an optical cross-connect. We show switching times of less than 10 ms and optical power stability of better than 0.2 dB. The mirrors, made from 10-μm-thick single-crystal silicon and with a radius of 400-450 μm, are able to tilt to 8° corresponding to 80% of touchdown angle. This is achieved using a nonlinear closed-loop control algorithm, which also results in a maximum actuation voltage of 85 V, and a pointing accuracy of less than 150 μrad. This paper will describe the MEMS mirror and actuator design, modeling, servo design, and measurement results.

Keywords

closed loop systems; electrostatic actuators; micromirrors; nonlinear control systems; optical switches; servomechanisms; silicon; 10 micron; 400 to 450 micron; 85 V; Si; double-gimbaled MEMS mirrors; electrostatic actuator; full closed-loop control; large port-count optical switch; maximum actuation voltage; microelectromechanical systems; nonlinear closed-loop control algorithm; nonlinear servo control; optical cross-connect; optical power stability; single-crystal silicon; switching time; torsional spring; Micromechanical devices; Mirrors; Nonlinear optics; Optical control; Optical design; Optical switches; Servosystems; Silicon; Stability; Voltage control; Electrostatic actuator; microelectromechanical systems (MEMS); nonlinear closed-loop control; optical cross-connects; snap-down; torsional spring;

fLanguage

English

Journal_Title

Microelectromechanical Systems, Journal of

Publisher

ieee

ISSN

1057-7157

Type

jour

DOI

10.1109/JMEMS.2004.839827

Filename

1416903