Visualization of Vibration In MEMS Resonators Using Stroboscopic Differential Interference Contrast Microscopy with Enhanced Temporal Resolution

We report a novel stroboscopic differential interference contrast (DIC) microscopy for the visualization of vibrations in MEMS devices, with a high vertical resolution at the nanometer (nm) scale, and a large vertical measurement range of ~1 um compared to state of the art. It enables the analysis of not only the linear vibrations but also the nonlinear fluctuations in the vibration conditions. The DIC microscopy measures the interference of two sheared illumination light beams reflected from the sample surface to determine the differential surface deflection, and a stroboscopic method is used to capture the fast vibration motions of the MEMS device. Furthermore, we introduce a doubly-modulated illumination method to enhance the temporal resolution of the stroboscopic method, which is promising for investigating of fast transition dynamics in MEMS resonators.