US5140559A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low flow-noise conformal fiber optic hydrophone
Assignee: United States Department of the Navy
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Filing: 1991-02-21
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Granted: 1992-08-18
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Expires: 2011-02-21
Abstract
Abstract A fiber-optic hydrophone having a pair of jacketed fiber optic windings fed in a concentric planar spiral configuration in a layer of polyurethane is provided. One of the fiber optic windings has a fiber with a bonded acoustically sensitive jacket thereby increasing its sensitivity to acoustic energy. The second fiber optic winding, the reference winding, has a unbonded jacket enclosing the fiber resulting in reduced sensitivity to acoustic energy. Sensitivity to vibrational energy; however, is not reduced. The combining of signals from the pair of fibers provides a vibration-canceled acoustic signal.
Inventors
- 👤 Stanley A. Fisher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 21:16
CPC Classifications
G; G01; G01H; G01H9/00; G01H9/004
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
138 words
A vibration-canceling fiber optic hydrophone comprising: a. a sensing coil formed with an optical fiber having a jacket which is acoustically sensitive bonded to the optical fiber; b. a reference coil formed with an optical fiber having a protective jacket that is not bonded to the optical fiber; c. a planar acoustic sensing disk formed by forming said sensing coil and reference coil into a planar concentric spiral; d. an acoustically transparent material encapsulating said planar acoustic sensing disk thereby forming a sealed, compliant planar layer; e. a coherent light source connected to and transmitting light to said reference optical fiber and to said sensing optical fiber; and f. an opto-electronic unit connected to and receiving transmitted light from said reference and sensing optical fibers suitable for determining phase shift differences between said sensing and reference optical fibers.
Claim 2
Dependent Claim
138 words
A vibration-canceling fiber optic hydrophone comprising: a. a sensing coil formed with an optical fiber having a jacket which is acoustically sensitive bonded to the optical fiber; b. a reference coil formed with an optical fiber having a protective jacket that is not bonded to the optical fiber; c. a planar acoustic sensing disk formed by forming said sensing coil and reference coil into a planar concentric spiral; d. an acoustically transparent material encapsulating said planar acoustic sensing disk thereby forming a sealed, compliant planar layer; e. a coherent light source connected to and transmitting light to said reference optical fiber and to said sensing optical fiber; and f. an opto-electronic unit connected to and receiving transmitted light from said reference and sensing optical fibers suitable for determining phase shift differences between said sensing and reference optical fibers.
Claim 3
Dependent Claim
75 words
A vibration-canceling fiber optic hydrophone comprising: a. means for providing coherent light; b. means for receiving coherent light, said receiving means having optical characteristics which vary when subjected to acoustic impingement; c. means for detecting vibration signals, said detecting means being insulated from acoustic impingement; d. means for processing output signals from said receiving means and said detecting means; and e. means for demodulating processed output signals to obtain a low vibration noise acoustic signal.
Claim 4
Dependent Claim
75 words
A vibration-canceling fiber optic hydrophone comprising: a. means for providing coherent light; b. means for receiving coherent light, said receiving means having optical characteristics which vary when subjected to acoustic impingement; c. means for detecting vibration signals, said detecting means being insulated from acoustic impingement; d. means for processing output signals from said receiving means and said detecting means; and e. means for demodulating processed output signals to obtain a low vibration noise acoustic signal.
Claim 5
Dependent Claim
21 words
A vibration-canceling fiber optic hydrophone as in claim 2 wherein said means for providing coherent light is a laser light source.
Claim 6
Dependent Claim
22 words
A vibration-canceling fiber optic hydrophone as in claim 3 wherein said laser light source emits light at a wavelength of 800 nM.
Claim 7
Dependent Claim
22 words
A vibration-canceling fiber optic hydrophone as in claim 3 wherein said laser light source emits light at a wavelength of 1300 nM.
Claim 8
Dependent Claim
43 words
A vibration-canceling fiber optic hydrophone as in claim 2 wherein said means for receiving coherent light is a fiber optic coil having an acoustically sensitive jacket continuously bonded to the fiber optic coil and wound on a compliant sheet of acoustically transparent material.
Claim 9
Dependent Claim
16 words
A vibration-canceling fiber optic hydrophone as in claim 6 wherein said acoustically transparent material is polyurethane.
Claim 10
Dependent Claim
43 words
A vibration-canceling fiber optic hydrophone as in claim 2 wherein said means for detecting vibration signals comprises a fiber optic coil having a jacket that is not bonded to the fiber optic coil and wound on a compliant sheet of acoustically transparent material.
Claim 11
Dependent Claim
16 words
A vibration-canceling fiber optic hydrophone as in claim 8 wherein said acoustically transparent material is polyurethane.
Claim 12
Dependent Claim
41 words
A vibration-canceling fiber optic hydrophone as in claim 2 wherein said means for receiving coherent light and said means for detecting vibration signals each comprise a fiber optic coil with the coils collocated on a compliant; sheet and form concentric windings.
Claim 13
Dependent Claim
29 words
A vibration-canceling fiber optic hydrophone as in claim 2 wherein said means for processing output signals is an optical-electronic processor having an optical phase detector, photo-voltage converter, and preamplifier.
Claim 14
Dependent Claim
21 words
A vibration-canceling fiber optic hydrophone as in claim 2 wherein said means for demodulating is a device using synthetic heterodyne demodulation.
References Cited (Backward Citations)
US4166932A
Cited
US4162397A
Cited
US4300727A
Cited
US4446543A
Cited
US4297887A
Cited
US4363114A
Cited
US4449210A
Cited
US4527749A
Cited
US4624570A
Cited
US4649529A
Cited
US4994668A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-08-18 | 1996-02-17 | 1996-08-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-08-18 | 2000-02-17 | 2000-08-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-08-18 | 2004-02-17 | 2004-08-18 | $7700.00 | Window Closed / Lapsed |