Vibration measurement of a micro-structure by digital holographic microscopy

A method for the vibration measurement of a micro-electro-mechanical system (MEMS) structure based on digital holographic microscopy (DHM) is presented. A sequence of digital holograms of a vibrating micro-beam excited by varying voltage is captured by a high-speed CCD camera. The phase changes of the object at different instants are obtained by digital reconstruction. The displacement, velocity and acceleration are evaluated by both spatial and temporal Fourier and windowed Fourier analyses. The results show that digital holographic microscopy with Fourier analyses is an effective method for evaluating the dynamic characteristics of a MEMS component.