Highly-Linearized Heterodyne Self-Mixing Vibrometer

Abstract

Vibration meters based on self-mixing interferometry are generally made in baseband, without modulations, because it is very difficult to obtain a linear modulation of the wavelength by controlling the supply current. In this paper, it is shown a multi-frequency modulation strategy for a heterodyne self-mixing vibrometer, which allows us to overcome the limits of frequency estimation algorithms and can work on a diffusing target up to a few meters away.