US4701614A
Expired / Lapsed
US
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Fiber optic pressure sensor
Assignee: APPLIED PHOTONIC DEVICES Inc
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Filing: 1984-06-25
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Granted: 1987-10-20
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Expires: 2004-06-25
Abstract
Abstract An arrangement for an optical fiber pressure sensor is described. This sensor is comprised of two coating layers concentrically clad to and coaxially oriented with an optical fiber. The first coating layer is comprised of a relatively hard optically lossy material which absorbs any light radiating outwardly from the optical fiber. The second coating layer is comprised of a compliant material in which granular particles have been uniformly dispersed. In response to any pressure laterally applied to the sensor, the compliant coating layer imparts micro-bends, onto the optical fiber, which, in turn, couple light from propagating modes to non-propagating modes. As a result, the amplitude (or power) of the light exiting the optical fiber advantageously decreases in response to this pressure.
Inventors
- 👤 Raymond E. Jaeger
- 👤 Mohd Aslami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 14:55
CPC Classifications
G; G01; G01L; G01L1/00; G01L1/24; G01L1/242; G01L1/243; G01L1/245; G08; G08B; G08B13/00; G08B13/18; G08B13/181; G08B13/183; G08B13/186
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
50 words
An optical fiber pressure sensor comprising: an optically transmissive fiber, a layer of optically lossy material concentrically clad to the optical fiber and coaxially oriented therewith, and a compliant layer, having a dispersion of granular particles therein, concentrically clad to the lossy layer and coaxially oriented with the optical fiber.
Claim 2
Dependent Claim
50 words
An optical fiber pressure sensor comprising: an optically transmissive fiber, a layer of optically lossy material concentrically clad to the optical fiber and coaxially oriented therewith, and a compliant layer, having a dispersion of granular particles therein, concentrically clad to the lossy layer and coaxially oriented with the optical fiber.
Claim 3
Dependent Claim
26 words
The sensor in claim 1 wherein the optically lossy layer is comprised of a material that is substantially harder than the material comprising the compliant layer.
Claim 4
Dependent Claim
14 words
The sensor in claim 2 wherein the particles are substantially comprised of particulate matter.
Claim 5
Dependent Claim
16 words
The sensor in claim 1 wherein the granular particles are uniformly dispersed throughout the compliant layer.
Claim 6
Dependent Claim
15 words
The sensor in claim 4 wherein the particulate matter is comprised of sand or grit.
Claim 7
Dependent Claim
45 words
The sensor in claim 3 wherein the optical fiber is comprised of an optically transmissive core and at least one cladding layer, concentrically surrounding said core and coaxially oriented therewith, wherein said cladding layer has an index of refraction different from that of said core.
Claim 8
Dependent Claim
118 words
An arrangement for a pressure detector comprising: (a) an optical fiber pressure sensor having (1) an optically transmissive fiber, (2) a layer of optically lossy material concentrically clad to the optical fiber and coaxially oriented therewith, and (3) a compliant layer having a dispersion of granular particles therein, concentrically clad to the lossy layer, and coaxially oriented with the optical fiber, (b) means for producing light and injecting the light into one end of the optical fiber, and (c) means for detecting any light exiting from the other end of the optical fiber, and, in response to a pre-determined change in the exiting light, producing an indication that pressure has been applied to the optical fiber pressure sensor.
Claim 9
Dependent Claim
118 words
An arrangement for a pressure detector comprising: (a) an optical fiber pressure sensor having (1) an optically transmissive fiber, (2) a layer of optically lossy material concentrically clad to the optical fiber and coaxially oriented therewith, and (3) a compliant layer having a dispersion of granular particles therein, concentrically clad to the lossy layer, and coaxially oriented with the optical fiber, (b) means for producing light and injecting the light into one end of the optical fiber, and (c) means for detecting any light exiting from the other end of the optical fiber, and, in response to a pre-determined change in the exiting light, producing an indication that pressure has been applied to the optical fiber pressure sensor.
Claim 10
Dependent Claim
25 words
The arrangement in claim 7 wherein the lossy layer is comprised of a material that is substantially harder than the material comprising the compliant layer.
Claim 11
Dependent Claim
14 words
The apparatus in claim 8 wherein the particles are substantially comprised of particulate matter.
Claim 12
Dependent Claim
16 words
The arrangement in claim 7 wherein the granular particles are uniformly dispersed throughout the compliant layer.
Claim 13
Dependent Claim
15 words
The apparatus in claim 10 wherein the particulate matter is comprised of sand or grit.
Claim 14
Dependent Claim
45 words
The arrangement in claim 9 wherein the optical fiber is comprised of an optically transmissive core and at least one cladding layer concentrically surrounding the core and coaxially oriented therewith, wherein said cladding layer has an index of refraction different from that of said core.
References Cited (Backward Citations)
US4342907A
Cited
US4530078A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-10-19 | 1991-04-20 | 1991-10-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-10-19 | 1995-04-20 | 1995-10-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-10-19 | 1999-04-20 | 1999-10-20 | $7700.00 | Window Closed / Lapsed |