Patent US5140559A successfully refreshed from Google Patents.
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 21:41
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.
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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 |