Title :
Stabilized Stroboscopic Full-Field Interferometer for Characterization of Subnanometer Surface Vibrations
Author :
Lipiainen, Lauri ; Kokkonen, Kimmo ; Kaivola, Matti
Author_Institution :
Dept. of Appl. Phys., Aalto Univ., Espoo, Finland
Abstract :
The ongoing rapid development of digital camera technology together with increasing computing power enabling fast image analysis has opened up possibilities to further advance the performance of full-field interferometry. We present a software-based stabilization method for stroboscopic homodyne full-field interferometry that enables phase sensitive absolute-amplitude measurements of surface vibrations in microelectromechanical devices. The reference signal for the stabilization is obtained from a freely selectable region in the acquired interference images, resulting in a compact interferometer design without the need for additional optical components for monitoring the operation point. The proposed stabilization method is implemented in an LED-based stroboscopic Michelson-type full-field interferometer. To demonstrate the performance of the setup, an out-of-plane vibration field at 12 MHz in a square-plate silicon resonator is characterized. The data analysis reveals that a minimum detectable amplitude of less than 30 pm is achieved in the measurement. These first results already demonstrate the potential of the software-stabilization concept and serve to advance the detection of low-amplitude surface vibrations with full-field interferometry.
Keywords :
Michelson interferometers; data analysis; elemental semiconductors; light emitting diodes; light interference; light interferometry; microsensors; optical resonators; optical sensors; silicon; surface dynamics; surface topography measurement; vibration measurement; LED-based stroboscopic Michelson-type full-field interferometer; Si; data analysis; digital camera technology; frequency 12 MHz; image analysis; interference image acquisition; low-amplitude surface vibration detection; microelectromechanical device; optical component; phase sensitive absolute amplitude measurement; software-based stabilization method; square-plate silicon resonator; stabilized stroboscopic full-field interferometer; stroboscopic homodyne full-field interferometry; subnanometer surface vibration characterization; Cameras; Optical imaging; Optical interferometry; Optical resonators; Optical surface waves; Vibration measurement; Vibrations; Vibration measurement; acoustic devices; full-field; homodyne detection; homodyne detection.; interferometry; microelectromechanical devices; surface vibrations;
Journal_Title :
Microelectromechanical Systems, Journal of
DOI :
10.1109/JMEMS.2015.2428433