2010/04/30 by Onur Kilic, Michel J. F. Digonnet, Gordon S. Kino +1 · 2 citations
Earth and Planetary Sciences · Engineering · Physics and Astronomy · #Advanced Fiber Optic Sensors #Seismic Waves and Analysis #Underwater Acoustics Research #physics.ao-ph #physics.ins-det #physics.optics
paper · pdf · doi:10.1121/1.3543949
published as Journal of Acoustical Society of America (March 2011)
arxiv created 2010/12/13 · openalex publication_date 2011/04/01 · arxiv updated 2015/05/18 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
This work reports on an optical hydrophone that is insensitive to hydrostatic pressure, yet capable of measuring acoustic pressures as low as the background noise in the ocean in a frequency range of 1 Hz to 100 kHz. The miniature hydrophone consists of a Fabry-Perot interferometer made of a photonic-crystal reflector interrogated with a single-mode fiber, and is compatible with existing fiber-optic technologies. Three sensors with different acoustic power ranges placed within a sub-wavelength sized hydrophone head allow a high dynamic range in the excess of 160 dB with a low harmonic distortion of better than -30 dB. A method for suppressing cross coupling between sensors in the same hydrophone head is also proposed. A prototype was fabricated, assembled, and tested. The sensitivity was measured from 100 Hz to 100 kHz, demonstrating a minimum detectable pressure down to 12 μPa (1-Hz noise bandwidth), a flatband wider than 10 kHz, and very low distortion.