Self-Mixing Vibrometer with Real-Time Digital Signal Elaboration

This work describes the development of an optical sensor for vibration measurement without contact. The realized vibrometer is based on real-time digital elaboration of the signal obtained by a self-mixing interferometer, with an embedded autofocus system. Two different algorithms are implemented, for the continuous working on various diffusive surfaces, with different levels of optical reflectivity. Thanks to the autofocus and digital processing, the proposed sensor is easy to use and requires no assistance of a skilled operator.