US4929049A
Expired / Lapsed
US
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Fiber optic refractive index sensor using a metal clad
Assignee: FiberChem Inc
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Filing: 1988-01-29
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Granted: 1990-05-29
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Expires: 2008-01-29
Abstract
Abstract A refractive index FOCS has a thin metal film clad on a fiber optic core so that transmission through the core is strongly affected by the refractive index of a surrounding solvent. The clad is made of platinum, or also of gold, rhodium or palladium. With a fluorescent tip, the changes in the fluorescent signal are a measure of the solvent refractive index. With a reflective tip, the changes in the reflected signal are measured. In a linear configuration, source and detector are placed at opposite ends of the fiber and changes in the transmitted signal are measured as a function of solvent refractive index.
Inventors
- 👤 Donald Le Goullon
- 👤 Kisholoy Goswami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 02:15
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/02; G01; G01N; G01N21/00; G01N21/17; G01N21/41; G01N21/43; G01N21/431; G01N2021/432
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
64 words
A fiber optic sensor for differentiating solvents of different refractive index, comprising: a fiber optic core; a thin film metal clad made of a material selected from platinum, rhodium and palladium formed on and surrounding the fiber optic core of a thickness which modulates the transmission of light through the fiber optic core as a function of the refractive index of a surrounding solvent.
Claim 2
Dependent Claim
64 words
A fiber optic sensor for differentiating solvents of different refractive index, comprising: a fiber optic core; a thin film metal clad made of a material selected from platinum, rhodium and palladium formed on and surrounding the fiber optic core of a thickness which modulates the transmission of light through the fiber optic core as a function of the refractive index of a surrounding solvent.
Claim 3
Dependent Claim
29 words
The sensor of claim 1 further comprising: a reflective tip formed at a tip of the fiber optic core with the thin film clad adjacent to the reflective tip.
Claim 4
Dependent Claim
43 words
The sensor of claim 1 further comprising: a light source operatively associated with the fiber optic core for inputting a light signal into the core; detection means operatively associated with the fiber optic core for detecting a signal from the fiber optic core.
Claim 5
Dependent Claim
15 words
The sensor of claim 1 wherein the thin film metal clad is made of platinum.
Claim 6
Dependent Claim
15 words
The sensor of claim 1 wherein the thin film metal clad is made of rhodium.
Claim 7
Dependent Claim
15 words
The sensor of claim 1 wherein the thin film metal clad is made of palladium.
Claim 8
Dependent Claim
28 words
The sensor of claim 1 wherein the metal clad has a thickness of up to about the penetration depth of an evanescent wave propagating through the fiber core.
Claim 9
Dependent Claim
76 words
A fiber optic sensor for differentiating solvents of different refractive index, comprising: a fiber optic core; a thin film metal clad formed on and surrounding the fiber optic core of a thickness such that the transmission of light through the fiber optic core is a function of the refractive index of a surrounding solvent; a fluorescent material immobilized at a tip of the fiber optic core with the thin film clad adjacent to the fluorescent tip.
Claim 10
Dependent Claim
76 words
A fiber optic sensor for differentiating solvents of different refractive index, comprising: a fiber optic core; a thin film metal clad formed on and surrounding the fiber optic core of a thickness such that the transmission of light through the fiber optic core is a function of the refractive index of a surrounding solvent; a fluorescent material immobilized at a tip of the fiber optic core with the thin film clad adjacent to the fluorescent tip.
Claim 11
Dependent Claim
25 words
The sensor of claim 8 further comprising: excitation means for exciting the fluorescent material; detection means for detecting a fluorescent signal from the fluorescent material.
Claim 12
Dependent Claim
15 words
The sensor of claim 8 wherein the thin film metal clad is made of platinum.
Claim 13
Dependent Claim
22 words
The sensor of claim 8 wherein the thin film metal clad is made of a material selected from gold, rhodium and palladium.
Claim 14
Independent Claim
95 words
A method of detecting the refractive index of a solvent, comprising: forming a bare fiber optic core; forming a thin film metal clad of a material selected from Pt, Au, Rh and Pd on and surrounding the bare fiber optic core of a thickness such that the transmission of light through the fiber optic core is a function of the refractive index of a surrounding solvent; contacting the clad with a solvent; inputting a light signal into the core; detecting decreases in intensity of the inputted light signal after it is transmitted through the core.
Claim 15
Independent Claim
95 words
A method of detecting the refractive index of a solvent, comprising: forming a bare fiber optic core; forming a thin film metal clad of a material selected from Pt, Au, Rh and Pd on and surrounding the bare fiber optic core of a thickness such that the transmission of light through the fiber optic core is a function of the refractive index of a surrounding solvent; contacting the clad with a solvent; inputting a light signal into the core; detecting decreases in intensity of the inputted light signal after it is transmitted through the core.
Claim 16
Dependent Claim
22 words
The method of claim 1 further comprising: forming a reflective tip on the fiber core; detecting a reflected signal from the core.
Claim 17
Dependent Claim
30 words
The method of claim 12 further comprising: inputting the light signal at one end of the fiber core; detecting a transmitted signal at the other end of the fiber core.
Claim 18
Independent Claim
94 words
A method of detecting the refractive index of a solvent, comprising: forming a bare fiber optic core; forming a thin film metal clad on and surrounding the bare fiber optic core of a thickness such that the transmission of light through the fiber optic core is a function of the refractive index of a surrounding solvent; forming a fluorescent tip on the fiber core; contacting the clad with a solvent; inputting a light signal into the core of a wavelength selected to excite fluorescence of the tip; detecting a fluorescent signal from the core.
Claim 19
Independent Claim
94 words
A method of detecting the refractive index of a solvent, comprising: forming a bare fiber optic core; forming a thin film metal clad on and surrounding the bare fiber optic core of a thickness such that the transmission of light through the fiber optic core is a function of the refractive index of a surrounding solvent; forming a fluorescent tip on the fiber core; contacting the clad with a solvent; inputting a light signal into the core of a wavelength selected to excite fluorescence of the tip; detecting a fluorescent signal from the core.
Claim 20
Dependent Claim
23 words
The method of claim 13 further comprising: forming the thin film metal clad of a material selected from Pt, Au, Rh, and Pd.
Claim 21
Independent Claim
66 words
A method of forming a refractive index fiber optic chemical sensor, comprising: forming a bare fiber optic core; forming a thin film metal clad of a metal selected from Pt, Rh and Pd on and surrounding the bare fiber optic core of a thickness which modulates the transmission of light through the fiber optic core as a function of the refractive index of a surrounding solvent.
Claim 22
Independent Claim
66 words
A method of forming a refractive index fiber optic chemical sensor, comprising: forming a bare fiber optic core; forming a thin film metal clad of a metal selected from Pt, Rh and Pd on and surrounding the bare fiber optic core of a thickness which modulates the transmission of light through the fiber optic core as a function of the refractive index of a surrounding solvent.
Claim 23
Dependent Claim
25 words
The method of claim 17 further comprising: forming the metal clad by painting the bare core with a metallic paint and heating the painted core.
Claim 24
Dependent Claim
13 words
The method of claim 17 further comprising forming the metal clad of Pt.
Claim 25
Dependent Claim
18 words
The method of claim 17 further comprising: forming the metal clad of a thickness of a few monolayers.
Claim 26
Dependent Claim
30 words
The method of claim 17 further comprising forming the metal clad of a thickness of up to about the penetration depth of an evanescent wave propagating through the fiber core.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-05-28 | 1993-11-27 | 1994-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-05-28 | 1997-11-27 | 1998-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-05-28 | 2001-11-27 | 2002-05-29 | $7700.00 | Window Closed / Lapsed |