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US5525800A
Expired / Lapsed
US
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Selective multi-chemical fiber optic sensor
Assignee: United States Department of the Navy
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Filing: 1994-10-31
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Granted: 1996-06-11
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Expires: 2014-10-31
Abstract
Abstract A fiber optic sensor for detecting at least one chemical by evanescent wave spectroscopy comprises a generator of a light signal, a mirror for introducing the light signal into a fiber, a clad optical chalcogenide glass fiber, a mirror for directing the light signal from the fiber into a detector, and a detector for detecting chemicals by the fiber. The fiber comprises a core and a clad having lower refractive index than the core enveloping and being in continuous contact with the core, at least one region on the fiber completely or partially devoid of the clad, and a polymer disposed in the region having affinity for the chemical(s). There being a different polymer in each region if there is more than one region.
Inventors
- 👤 Jasbinder S. Sanghera
- 👤 Pablo C. Pureza
- 👤 Ishwar D. Aggarwal
- 👤 Gregory Nau
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 12:54
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/75; G01N21/77; G01N21/7703; G01N2021/7706; G01N2021/7709; G01N2021/773; G01N2021/7793
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
90 words
A fiber optic sensor comprising a fiber; said fiber comprising a core and a clad having a lower refractive index than that of said core, said clad being in contact with said core; said fiber also comprising at least one region which is partially or totally unclad; a polymer disposed in said at least one region, said polymer having a lower refractive index than that of said core; said core being made of glass containing an element selected from the group consisting of sulfur, selenium, tellurium, polonium, and mixtures thereof.
Claim 2
Dependent Claim
90 words
A fiber optic sensor comprising a fiber; said fiber comprising a core and a clad having a lower refractive index than that of said core, said clad being in contact with said core; said fiber also comprising at least one region which is partially or totally unclad; a polymer disposed in said at least one region, said polymer having a lower refractive index than that of said core; said core being made of glass containing an element selected from the group consisting of sulfur, selenium, tellurium, polonium, and mixtures thereof.
Claim 3
Dependent Claim
58 words
The fiber sensor of claim 1 wherein the diameter of said fiber core and clad is about 20-500 microns; the diameter of said core is about 10-90% of the total diameter of said core and clad; and said core is made of glass containing an element selected from the group consisting of sulfur, selenium, tellurium, and mixtures thereof.
Claim 4
Dependent Claim
26 words
The fiber sensor of claim 2 wherein said clad is glass comprising an element selected from the group consisting of sulfur, selenium, tellurium, and mixtures thereof.
Claim 5
Dependent Claim
26 words
The fiber sensor of claim 3 wherein the longitudinal extent of said at least one region is about 0.1-25 cm and said clad envelopes said core.
Claim 6
Dependent Claim
37 words
The fiber sensor of claim 3 wherein the diameter of said core is about 30-70% of the total diameter of said core and clad; and longitudinal extent of said at least one region is about 0.1-25 cm.
Claim 7
Dependent Claim
41 words
The fiber sensor of claim 5 wherein said at least one region is completely devoid of said clad, said polymer is disposed over said core in the form of a sleeve, and said fiber comprising two or more of said regions.
Claim 8
Dependent Claim
53 words
The fiber sensor of claim 6 wherein each of said at least one regions is in the range of 0.1-25 cm in longitudinal extent along said fiber, each of said at least one regions is spaced from each other, and a different polymer is disposed in each of said at least one regions.
Claim 9
Dependent Claim
35 words
The fiber sensor of claim 7 including means for generating a light signal, means for introducing the light signal into said fiber, and means for directing the light signal from said fiber into a detector.
Claim 10
Dependent Claim
60 words
The fiber sensor of claim 8 wherein said means for generating a light signal is a broadband source, said means for introducing the light into said fiber and said means for directing the light source from said fiber is at least one mirror, and said means for detecting spectra of chemicals in said polymers is a Fourier transform infrared spectrometer.
Claim 11
Dependent Claim
28 words
The fiber sensor of claim 9 wherein said polymer on one of said regions is polydimethylsiloxane and said polymer in another of said regions is low density polyethylene.
Claim 12
Dependent Claim
42 words
The fiber sensor of claim 9 wherein each of said at least one regions includes a polymer coating disposed around and in contact with said core, each of said polymers being hydrophobic and distinct from any other polymer disposed on said fiber.
Claim 13
Dependent Claim
98 words
A fiber sensor for sensing at least one chemical having minimum detection limit below the ppm level comprising a fiber; said fiber comprising a core and a clad having a lower refractive index than said core, said clad enveloping and being in contact with said core; said fiber also comprising at least one region which is unclad; a polymer coating in said at least one region having lower refractive index than said core; said core and said clad being made of glass comprising an element selected from the group consisting of sulfur, selenium, tellurium, polonium, and mixtures thereof.
Claim 14
Dependent Claim
98 words
A fiber sensor for sensing at least one chemical having minimum detection limit below the ppm level comprising a fiber; said fiber comprising a core and a clad having a lower refractive index than said core, said clad enveloping and being in contact with said core; said fiber also comprising at least one region which is unclad; a polymer coating in said at least one region having lower refractive index than said core; said core and said clad being made of glass comprising an element selected from the group consisting of sulfur, selenium, tellurium, polonium, and mixtures thereof.
Claim 15
Dependent Claim
65 words
The fiber sensor of claim 12 wherein the diameter of said fiber core and clad is about 20-500 microns; the diameter of said core is in the range of about 10-90% of the total diameter of said core and clad; and said core and said clad being made of glass comprising an element selected from the group consisting of sulfur, selenium, tellurium, and mixtures thereof.
Claim 16
Dependent Claim
18 words
The fiber sensor of claim 13 wherein the longitudinal extent of said unclad region is about 0.1-25 cm.
Claim 17
Dependent Claim
24 words
The fiber sensor of claim 14 wherein the diameter of said core is about 30-70% of the total diameter of said core and clad.
Claim 18
Dependent Claim
54 words
The fiber sensor of claim 15 wherein said unclad region is completely unclad; said polymer is disposed over said core in the form of a sleeve; one of said at least one region has a coating of polydimethylsiloxane and another one of said at least region region has a coating of low density polyethylene.
Claim 19
Dependent Claim
41 words
The fiber sensor of claim 16 wherein each of said unclad regions is about 0.1-25 cm in longitudinal extent along said fiber; said regions are spaced apart from each other; and a different polymer is coated in each of said regions.
Claim 20
Dependent Claim
42 words
The fiber sensor of claim 17 including means for generating a light signal; means for introducing the light signal into said fiber; means for directing the light signal from said fiber into a detector; and means for detecting chemicals in said polymers.
Claim 21
Dependent Claim
58 words
The fiber sensor of claim 18 wherein said means for generating a light signal is a broadband source; said means for introducing the light into said fiber and said means for directing the light source from said fiber is at least one mirror; and said means for detecting chemicals in said polymers is a Fourier transform infrared spectrometer.
Claim 22
Dependent Claim
42 words
The fiber sensor of claim 19 wherein each of said unclad regions includes a polymer in sleeve form disposed around and in contact with said core; each of said polymers being hydrophobic and distinct from any other polymer disposed on said fiber.
References Cited (Backward Citations)
US5239176A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-06-11 | 1999-12-11 | 2000-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-06-11 | 2003-12-11 | 2004-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-06-11 | 2007-12-11 | 2008-06-11 | $7700.00 | Window Closed / Lapsed |