An optical microscope, utilizing the principles oftime-average hologram interferometry, is described for
MicroElectroMechanical Systems (MEMS) applications. MEMS are devices fabricated via techniques such as
micro photolithography to create miniature actuators and sensors. Many ofthese sensors fmd their way into
applications which rely on, or depend upon, the dynamic behavior ofthe sensor. Typical dimensions of current
MEMS devices are measured in microns, and the current trend is to further decrease the size of MEMS devices to
submicron dimensions. However, the smaller MEMS become, the more challenging it is to measure with accuracy
the dynamic characteristics of these devices. In this paper, the theory and construction of an electro-optic
holographic microscope (EOHM) for the purpose ofstudying the dynamic behavior ofMEMS devices are described.
Additionally, by performing measurements within an EOHM image, object displacements are determined as
illustrated by representative examples. With the EOHM, MEMS devices with surface sizes ranging from
approximately 35 x400 microns down to 5 x 18 microns have been studied while undergoing resonant vibrations at
frequencies as high as 2 MHz.