Stroboscopic phase-shifting interferometry for dynamic characterization of optical MEMS

Matthew Richard Hart; Robert A. Conant; Kam Y. Lau; Richard S. Muller

doi:10.1117/12.354838

19 July 1999 Stroboscopic phase-shifting interferometry for dynamic characterization of optical MEMS

Matthew Richard Hart, Robert A. Conant, Kam Y. Lau, Richard S. Muller

Proceedings Volume 3749, 18th Congress of the International Commission for Optics; (1999) https://doi.org/10.1117/12.354838
Event: ICO XVIII 18th Congress of the International Commission for Optics, 1999, San Francisco, CA, United States

Abstract

Macro-scale optical components with surface flatness better than 25 nm over large areas (more than 1 X 1 mm) are widely available. However, the flatness of optical MEMS devices (for example micro-mirrors and -diffraction gratings) is often considerably worse. In addition to static deformation caused by film stresses and stress gradients, dynamic mechanical effects, such as air drag and excitation of higher-order resonant modes, cause surface deformations that are difficult to predict using theoretical or finite- element models. These deformations can cause significant degradation to optical performance. Dynamic measurements of nanometer-scale displacements across the entire surface of a micro-mirror are difficult or impossible to perform with conventional MEMS metrology techniques such as SEM, AFM, and optical microscopy. Stroboscopic interferometry, however, can be used to measure time-slice images that show 3D motion of fast-moving MEMS devices, with vertical resolution better than 1 nm. In this paper, we report the application of this technique to dynamic characterization of fold-up surface- micromachined structures and show how the method can be used to provide new insights into the optical and mechanical behavior of scanning micro-mirror devices.

Citation Download Citation

Matthew Richard Hart, Robert A. Conant, Kam Y. Lau, and Richard S. Muller "Stroboscopic phase-shifting interferometry for dynamic characterization of optical MEMS", Proc. SPIE 3749, 18th Congress of the International Commission for Optics, (19 July 1999); https://doi.org/10.1117/12.354838

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available