Vibrometry for MEMS

Measuring vibrations of MEMS through a packaging of silicon is made possible by confocal imaging with an IR light source.  
SmarAct Metrology’s PicoScale Vibrometer is a turnkey solution to measure vibrations of micromechanical structures with sizes that range from just a few µm to multiples cm. Therefore, the selective imaging of layers with infrared confocal microscopy can be made possible. They can measure through semi-transparant materials such as glass and silicon as well as semi-transparent structures when in focus.
In-plane motion is imaged by recording a sequence of microscopy images that span exactly one vibration cycle, like stroboscopic imaging. In plane vibrations down to 10nm can be extracted through optical flow algorithms.