In-Plane and Out-Of-Plane Analyses of Encapsulated Mems Device by IR Laser Vibrometry

Microelectromechanical systems (MEMS) are often packaged in silicon enclosures that keep their microenvironment well controlled, a crucial aspect for their good operation. With conventional optical techniques, it is however impossible to evaluate their dynamic performance without opening up their enclosures and subsequently disturbing their working conditions. The vibrometry technology that is presented here utilizes an infrared (IR) laser source and a confocal detection scheme, which paves the way to analyze the behavior of multilayered silicon-encapsulated MEMS, whether it comes to in-plane or out-of-plane vibrations.