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Proceedings Paper

Novel optical vibration sensor using external cavity feedback
Author(s): Christine Mignosi; Roger P. Griffiths; Michael Bordovsky; Christopher N. Morgan; Ian H. White; Nicholas A. J. Lieven
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Paper Abstract

A novel low cost, non-contact optical vibration sensor requiring only a single optoelectronic component has been developed. It consists of a CW semiconductor laser operating with external optical feedback. The laser beam reflected from a target generates a series of lasing modes set by the external cavity length. Beating of the modes produces an RF signal and this signal is detected as a variation in the junction voltage. Any change in the external cavity length induces corresponding beat frequency variations in the RF signal, which are transformed into amplitude variations using a simple edge-detection filter system. Using this sensor, low amplitude vibrations have been measured at frequencies of up to 600 Hz. Successful results have been achieved with target reflectivities lower than 5%. When calibrated, the sensor demonstrates satisfactory output for submicron vibration amplitudes. Maximum amplitudes of 1 mm have been measured with an accuracy of 0.2%.

Paper Details

Date Published: 14 April 1999
PDF: 9 pages
Proc. SPIE 3626, Testing, Packaging, Reliability, and Applications of Semiconductor Lasers IV, (14 April 1999); doi: 10.1117/12.345438
Show Author Affiliations
Christine Mignosi, Univ. of Bristol (United Kingdom)
Roger P. Griffiths, RDP Electronics Ltd. (United Kingdom)
Michael Bordovsky, Univ. of Bristol (United Kingdom)
Christopher N. Morgan, Univ. of Bristol (United Kingdom)
Ian H. White, Univ. of Bristol (United Kingdom)
Nicholas A. J. Lieven, Univ. of Bristol (United Kingdom)

Published in SPIE Proceedings Vol. 3626:
Testing, Packaging, Reliability, and Applications of Semiconductor Lasers IV
Mahmoud Fallahi; S. C. Wang; Mahmoud Fallahi; Kurt J. Linden; S. C. Wang, Editor(s)

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