Open AccessHigh-sensitivity vibrometer based on FM self-mixing interferometry
Author(s) -
M. Norgia,
F Bandi,
Alessandro Pesatori,
Silvano Donati
Publication year - 2019
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1249/1/012020
Subject(s) - interferometry , laser doppler vibrometer , optics , frequency modulation , laser scanning vibrometry , amplitude modulation , optical modulation amplitude , laser , amplitude , mixing (physics) , modulation (music) , sensitivity (control systems) , laser diode , physics , bandwidth (computing) , laser power scaling , acoustics , optical amplifier , telecommunications , electronic engineering , computer science , engineering , quantum mechanics
We present a new optical instrument for vibrations measurement, based on a method to read the frequency modulation of a laser diode self-mixing interferometer. The laser source, when exposed to back-injection of its emitted power, is perturbed in frequency and amplitude (self-mixing effect). When the optical back-injection level is low, the self-mixing effect introduces a frequency and amplitude modulation (FM and AM) of the emitted optical field. We demonstrated with a prototype instrument that the performances of FM modulation, in terms of resolution, sensitivity and bandwidth, show an improvement of two order of magnitude with respect to well-known AM self-mixing interferometer.