Abstract
A requirement to advance consistency and predictability of Micro-Electro Mechanical System (MEMS) device has triggered research to have precise measurements and visual means to characterize dynamic parameters. Time resolved measurements of entire surface in a microdevice to nanometer level accuracy are difficult using conventional metrology system such as optical interferometer and optical microscopy. Laser Doppler Vibrometer (LDV) has found their applications to some extent. Due to Single point technique, scanning is a must in LDV which sets drawback for characterization in Microsystems. In this paper we propose the use of Acousto Optic Modulator (AOM) as a strobing device with a continuous wave laser to develop a stroboscopic interferometer for static and dynamic characterization of out of plane motion. Due to high random access time (typical 150 nanoseconds) AOM improves the capability of the tool to test MEMS devices of higher frequencies. Detail study is done on the strobe frequency to correlate the pulsating frequency of the laser by the AOM and the driven frequency of the microdevice. Theoretical modeling of the stroboscopic interferometer is carried out by formulating the understanding between strobe frequency and the MEMS device.