Development of a 50MHz optical fibre hydrophone for the characterisation of medical ultrasound fields.
(pp. pp. 1747-1750).
A wideband fibre optic hydrophone system based on a polymer film Fabry-Perot sensing interferometer has been developed for the measurement of medical ultrasound fields. The sensor transduction mechanism is based upon the interferometric detection of acoustically-induced changes in the optical thickness of the polymer film. The advantage of this concept is that it offers the prospect of providing sufficiently small element sizes to avoid spatial averaging at frequencies in the tens of MHz range. The sensor is interrogated using a fibre coupled tunable laser operating in the range 1520-1600nm. The acoustic performance of the sensor was characterised in terms of its sensitivity and frequency response by comparison with a calibrated PVDF membrane hydrophone. The noise-equivalent-pressure was approximately 3kPa over a 25MHz measurement bandwidth with a frequency response that extended to 50MHz. The concept lends itself to a wide range of applications, from the laboratory characterisation of medical ultrasound sources, to invivo measurement of therapeutic and diagnostic ultrasound. © 2005 IEEE.
|Title:||Development of a 50MHz optical fibre hydrophone for the characterisation of medical ultrasound fields|
|UCL classification:||UCL > School of BEAMS
UCL > School of BEAMS > Faculty of Engineering Science
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