Dynamic Morphology Detection of Microelectromechanical System Micromirror Using Digital Holography

Detecting the dynamic morphology of microelectromechanical system (MEMS) micromirror presents a challenge due to their small size, complex structure, and state of vibration. In this paper, we demonstrate that digital holography can be utilized to detect the dynamic parameters of MEMS micromirror, including displacement, deflection angle, and other parameters. We have constructed an off-axis digital holographic recording system and captured a sequence of holograms while operating the MEMS micromirror with both direct current (DC) and alternating current (AC) voltages. A self-tracking algorithm is proposed to measure accurately the deflection due to the vibration of the MEMS micromirror. Experimental results confirm that digital holography combined with the proposed algorithm can detect successfully the dynamic state of the vibrating MEMS micromirror. Detailed analyses of slight deflection angles and surface deformations have been conducted. This research introduces a new methodology for applications such as quality assessment and dynamic calibration of MEMS, as well as other dynamic analyses such as the use of acoustic waves in vibration deformation detection.