US4988863A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical fiber refractometer launching light at a non-zero launch angle
Assignee: GOVERNMENT OF UNITED STATES NAVY THE, Secretary of
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Filing: 1990-01-03
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Granted: 1991-01-29
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Expires: 2010-01-03
Abstract
Abstract The index of refraction of a liquid is measured using an optical fiber rectometer having a light transmitting optical fiber by immersing a portion of the optical fiber in the liquid and launching light into one end of the optical fiber at a selected non-zero launch angle with respect to the fiber axis. Light transmitted through the optical fiber is detected at the other end of the optical fiber and a determination is made of the index of refraction of the liquid in accordance with the detected light and the selected non-zero launch angle. By varying the launching angles of the light the range of the refractometer is increased. The light transmitting optical fiber is provided with a region having at least one tapered portion for further increasing the range of the refractometer. The tapered portion of the optical fiber is disposed between a refractive end of the optical fiber and the light source for providing single-ended operation.
Inventors
- 👤 Lloyd C. Bobb
- 👤 Howard D. Krumboltz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 14:51
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/41; G01N21/43; G01N21/431; G01N2021/432
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
91 words
A method for measuring the index of refraction of a liquid with an optical fiber refractometer having a light transmitting optical fiber with a fiber axis, comprising; immersing a portion of said optical fiber in said liquid, launching light into a first end of said optical fiber at a selected non-zero launch angle with respect to said fiber axis, detecting transmitted light at a second end of said optical fiber, and determining the index of refraction of said liquid in accordance with said detected light and said selected non-zero launch angle.
Claim 2
Independent Claim
91 words
A method for measuring the index of refraction of a liquid with an optical fiber refractometer having a light transmitting optical fiber with a fiber axis, comprising; immersing a portion of said optical fiber in said liquid, launching light into a first end of said optical fiber at a selected non-zero launch angle with respect to said fiber axis, detecting transmitted light at a second end of said optical fiber, and determining the index of refraction of said liquid in accordance with said detected light and said selected non-zero launch angle.
Claim 3
Dependent Claim
25 words
The method for measuring the index of refraction of claim 1 wherein the immersed portion of the optical fiber is provided with a tapered region.
Claim 4
Dependent Claim
34 words
The method for measuring the index of refraction of a liquid of claim 2 wherein said tapered region is disposed between a reflective end of said optical fiber and means for launching said light.
Claim 5
Dependent Claim
103 words
An optical fiber refractometer having a light transmitting optical fiber with a fiber axis and cladding surrounding a fiber core for measuring the index of refraction of a liquid, comprising: means for immersing a portion of said optical fiber in said liquid, means for launching light into a first end of said optical fiber at a selected non-zero launch angle with respect to said optical fiber axis, means for detecting transmitted light at a second end of said optical fiber, and means for determining the index of refraction of said liquid in accordance with the detected light and the selected non-zero launch angle.
Claim 6
Dependent Claim
103 words
An optical fiber refractometer having a light transmitting optical fiber with a fiber axis and cladding surrounding a fiber core for measuring the index of refraction of a liquid, comprising: means for immersing a portion of said optical fiber in said liquid, means for launching light into a first end of said optical fiber at a selected non-zero launch angle with respect to said optical fiber axis, means for detecting transmitted light at a second end of said optical fiber, and means for determining the index of refraction of said liquid in accordance with the detected light and the selected non-zero launch angle.
Claim 7
Dependent Claim
21 words
The optical fiber refractometer of claim 4, wherein the immersed portion of said optical fiber is provided with a tapered region.
Claim 8
Dependent Claim
27 words
The optical fiber refractometer of claim 5, wherein said tapered region is disposed between a reflective end of said optical fiber and said means for launching light.
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) | 1994-01-28 | 1994-07-30 | 1995-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-01-28 | 1998-07-30 | 1999-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-01-28 | 2002-07-30 | 2003-01-29 | $7700.00 | Window Closed / Lapsed |