Optical vibrometer based on Laser Diode Self-Mix Interferometry (SMI) is the elective choice in non-invasive vibration monitoring. We present an instrument aimed at measurement of small amplitude (10 nm < s < 1 μm) vibrations at very low frequency, below 10–3 Hz. Intended application is in situ vibration monitoring of artwork, e.g. during 3D surface topography aimed at indentification of the original piece to counteract forgery of the artwork, or to prevent or detect theft during transportation before/after an exhibition. In the intended application, long term stability and glitch-free operation are required. The proposed vibrometer exploits the fringe-lock configuration, and the advantages offered by the presence of the feedback loop. In previous design with AC feedback only, glitches were observed because of fringe lock loss due to wavelength fluctuation induced by temperature fluctuation, even with TEC control of the Laser Diode temperature.
Self-Mixing Laser Diode Vibrometer for Very Low Frequency applications
MARTINI, GIUSEPPE;RANDONE, ENRICO MARIA;DONATI, SILVANO
2013-01-01
Abstract
Optical vibrometer based on Laser Diode Self-Mix Interferometry (SMI) is the elective choice in non-invasive vibration monitoring. We present an instrument aimed at measurement of small amplitude (10 nm < s < 1 μm) vibrations at very low frequency, below 10–3 Hz. Intended application is in situ vibration monitoring of artwork, e.g. during 3D surface topography aimed at indentification of the original piece to counteract forgery of the artwork, or to prevent or detect theft during transportation before/after an exhibition. In the intended application, long term stability and glitch-free operation are required. The proposed vibrometer exploits the fringe-lock configuration, and the advantages offered by the presence of the feedback loop. In previous design with AC feedback only, glitches were observed because of fringe lock loss due to wavelength fluctuation induced by temperature fluctuation, even with TEC control of the Laser Diode temperature.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
