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We report on the development of a versatile vibrometer for characterizing in-plane microelectromechanical systems (MEMS) motion. It combines conventional optical components (microscope objective or macrozoom lens) and a home-made light-emitting diode (LED) stroboscope with incremental phase shifts. The system drives a digital charge-coupled device camera to record a video sequence of the moving MEMS “frozen” by the strobe LED at four equally spaced phases. The periodic motion of the specimen is accurately estimated by computing the values of displacements between successive images. We obtained the subpixel accuracy using an interpolation and correlation motion estimation algorithm. By using this technique, we analyzed vibrations of a silicon microprobe made for scanning probe microscopy. We determined both its natural vibration and mode shapes. The nanometer resolution of the displacement is reached using a microscope, and the mode shapes are imaged using a macrolens with a large field of view (10 mm). The experiments showed a good agreement with analytical predictions.

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