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Proceedings Paper

Heterodyne interferometer for in-situ and in-vivo vibration measurements in the inner ear
Author(s): R. Link; Edgar W. Fischer; E. Dalhoff; S. Heim; Hans J. Tiziani; Hans-Peter Zenner; Anthony W. Gummer
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Paper Abstract

Investigation of the inner ear is still the subject of basic research. The concept of an active filtering process in the mechano-electrical transfer mechanism in the inner ear (cochlea) was introduced. In this paper an optical approach detecting microvibrations is discussed. A fiber optic heterodyne interferometer with a miniaturized sensorhead was built. The fibers ensure flexibility and easy handling of the interferometer whereas the miniaturized sensorhead allows a non-invasive approach to the organ of Corti. In heterodyne interferometry as compared to classical interferometry two slightly different light frequencies for the reference and object beams are used. The vibration of the object is detected as a modulation of the phase of the detector signal. To obtain the information on the vibration two methods were analyzed and applied: namely measuring the amplitude of the sidebands in the spectrum of the modulated signal and secondly signal demodulation. It is possible to detect amplitudes down to 0.3 angstrom in a frequency range of 500 Hz to 50 kHz with a simulated object reflectivity of 0.02%.

Paper Details

Date Published: 1 February 1995
PDF: 7 pages
Proc. SPIE 2329, Optical and Imaging Techniques in Biomedicine, (1 February 1995); doi: 10.1117/12.200904
Show Author Affiliations
R. Link, Univ. Stuttgart (Germany)
Edgar W. Fischer, Univ. Stuttgart (Germany)
E. Dalhoff, Univ. Stuttgart (Germany)
S. Heim, Univ. Stuttgart (Germany)
Hans J. Tiziani, Univ. Stuttgart (Germany)
Hans-Peter Zenner, Univ. Tubingen (Germany)
Anthony W. Gummer, Univ. Tubingen (Germany)

Published in SPIE Proceedings Vol. 2329:
Optical and Imaging Techniques in Biomedicine
Hans-Jochen Foth; Aaron Lewis; Halina Podbielska; Michel Robert-Nicoud; Herbert Schneckenburger; Anthony J. Wilson, Editor(s)

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