Optical fiber interferometer for measuring the <bold>in situ </bold> deflection characteristics of microelectromechanical structures

Abstract

An optical fiber interferometer is described for measuring the out-of-plane displacement of microelectromechanical structures. The interferometric system has a theoretical measurement dynamic range greater than 10 8. Experimental results characterizing an electrostatically actuated polysilicon flexure beam are presented. The results are in good agreement with modeling data based on coupled boundary-element and finite-element analysis.

Integration of a fiber interferometer with a MEMS probe station

“…6 This combination yields a robust sensor tolerant of low frequency signal drift and angular misalignment of the fiber optic probe. The commercially-available digital demodulation system is based on a phase generated carrier demodulation technique 7 and is easily implemented.…”

“…6 When the MEMS VLEA was operated in it elastic regime, the maximum measured tip displacement was 1.22 μm. A relative measure of the reliability of the VLEA design can be appreciated from the fact that it has been operated in its elastic regime for more than 0.1 million cycles and no failures have been observed.…”

Optical system to characterize the gross contractile response of a tissue-equivalent collagen matrix

“…[12][13] With a few minor adjustments, this optical fiber interferometer system can detect the initiation of contraction with sensitivity in the tens of nanometers. It also has a wide dynamic range of measurement, up to 2 mm.…”

Modeling of a polyimide diaphragm for an optical pulse pressure sensor

“…MEMS diaphragm can be made from polymers by processes such as injection moulding, embossing and stereolithography [10]. Polymer diaphragm has been widely used for a limited detection space as presented in [11][12][13][14][15][16][17][18].…”