Acousto-optic effect compensation for optical determination of the normal velocity distribution associated with acoustic transducer radiation
Foote, Kenneth G.
Theobald, Peter D.
MetadataShow full item record
The acousto-optic effect, in which an acoustic wave causes variations in the optical index of refraction, imposes a fundamental limitation on the determination of the normal velocity, or normal displacement, distribution on the surface of an acoustic transducer or optically reflecting pellicle by a scanning heterodyne, or homodyne, laser interferometer. A general method of compensation is developed for a pulsed harmonic pressure field, transmitted by an acoustic transducer, in which the laser beam can transit the transducer nearfield. By representing the pressure field by the Rayleigh integral, the basic equation for the unknown normal velocity on the surface of the transducer or pellicle is transformed into a Fredholm equation of the second kind. A numerical solution is immediate when the scanned points on the surface correspond to those of the surface area discretization. Compensation is also made for oblique angles of incidence by the scanning laser beam. The present compensation method neglects edge waves, or those due to boundary diffraction, as well as effects due to baffles, if present. By allowing measurement in the nearfield of the radiating transducer, the method can enable quantification of edge-wave and baffle effects on transducer radiation. A verification experiment has been designed.
Author Posting. © Acoustical Society of America, 2015. This article is posted here by permission of Acoustical Society of America for personal use, not for redistribution. The definitive version was published in Journal of the Acoustical Society of America 138 (2015): 1627, doi:10.1121/1.4929372.
Showing items related by title, author, creator and subject.
Optical disk based acquisition system (ODAS) : description and report following the first deployment during the Prudhoe Bay experiment Spring 1987 (PRUDEX) von der Heydt, Keith (Woods Hole Oceanographic Institution, 1987-11)This is a report on the use of one vendor's optical disk system for the archiving of data in the field. Two Optimem 1000 units are part of an acquisition system used by the Arctic acoustics groups at Woods Hole Oceanographic ...
Stephen, Ralph A.; Bolmer, S. Thompson; Udovydchenkov, Ilya A.; Worcester, Peter F.; Dzieciuch, Matthew A.; Andrew, Rex K.; Mercer, James A.; Colosi, John A.; Howe, Bruce M. (Acoustical Society of America, 2013-10)Ocean bottom seismometer observations at 5000 m depth during the long-range ocean acoustic propagation experiment in the North Pacific in 2004 show robust, coherent, late arrivals that are not readily explained by ocean ...
Foote, Kenneth G.; Hastings, Mardi C.; Ketten, Darlene R.; Lin, Ying-Tsong; Reidenberg, Joy S.; Rye, Kent (Acoustical Society of America, 2012-02)Potential physical effects of sonar transmissions on marine mammals were investigated by measuring pressure fields induced in a 119-kg, 211-cm-long, young adult male common dolphin (Delphinus delphis) cadaver. The specimen ...