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Title: Fiber optic hydrophone

A miniature fiber optic hydrophone based on the principles of a Fabry-Perot interferometer. The hydrophone, in one embodiment, includes a body having a shaped flexible bladder at one end which defines a volume containing air or suitable gas, and including a membrane disposed adjacent a vent. An optic fiber extends into the body with one end terminating in spaced relation to the membrane. Acoustic waves in the water that impinge on the bladder cause the pressure of the volume therein to vary causing the membrane to deflect and modulate the reflectivity of the Fabry-Perot cavity formed by the membrane surface and the cleaved end of the optical fiber disposed adjacent to the membrane. When the light is transmitted down the optical fiber, the reflected signal is amplitude modulated by the incident acoustic wave. Another embodiment utilizes a fluid filled volume within which the fiber optic extends.
Authors:
 [1] ;  [1]
  1. (Livermore, CA)
Publication Date:
OSTI Identifier:
869294
Report Number(s):
US 5311485
DOE Contract Number:
W-7405-ENG-48
Resource Type:
Patent
Research Org:
Lawrence Livermore National Laboratory (LLNL), Livermore, CA
Country of Publication:
United States
Language:
English
Subject:
fiber; optic; hydrophone; miniature; fiber; optic; hydrophone; based; principles; fabry-perot; interferometer; hydrophone; embodiment; shaped; flexible; bladder; defines; volume; containing; air; suitable; gas; including; membrane; disposed; adjacent; optic; fiber; extends; terminating; spaced; relation; membrane; acoustic; waves; water; impinge; bladder; pressure; volume; therein; vary; causing; membrane; deflect; modulate; reflectivity; fabry-perot; cavity; formed; membrane; surface; cleaved; optical; fiber; disposed; adjacent; membrane; light; transmitted; optical; fiber; reflected; signal; amplitude; modulated; incident; acoustic; wave; embodiment; utilizes; fluid; filled; volume; fiber; optic; extends; volume containing; amplitude modulated; membrane surface; fluid filled; embodiment utilizes; fabry-perot interferometer; spaced relation; optic fiber; acoustic wave; acoustic wave; disposed adjacent; disposed adjacent; fiber optic; fiber optic; fiber optic; optical fiber; optical fiber; acoustic waves; cavity formed; suitable gas; reflected signal; fabry-perot cavity; containing air; shaped flexible; optic hydrophone; optic hydrophone /367/