Real-time vibration amplitude/phase imager using white-light interferometer and correlation image sensor

In this paper, we propose a real-time vibration amplitude/phase imaging technique for out-of-plane mechanical vibration detection and dynamic characterization of micro-structures. It is based on the white-light interferometry and the heterodyne detection scheme. Continuous motion is given to the interference fringe by scanning the reference mirror. The vibration generates beat frequencies between the modulation frequency by the scanning and the vibration frequency. A newly developed multiple channel correlation image sensor enables us to obtain sufficient number of frequency components to demodulate uniquely the vibration amplitude and phase two-dimetionally simultaneously. We show the system realizes a real-time observation of vibration modes of micro-structures at 45 frame per second with 320 × 256 spatial resolution. © 2010 the Institute of Electrical Engineers of Japan.