US3770350A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method utilizing an optical fiber raman cell
Assignee: AT&T Inc
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Filing: 1972-07-24
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Granted: 1973-11-06
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Expires: 1992-07-24
Abstract
Abstract A long length of liquid-core optical fiber is employed as a Raman cell, wherein the fiber core contains the material whose Raman spectrum is to be analyzed. Spectral intensifications of from 102 to 103 times greater than that obtained by conventional means are realized, using very small sample volumes. Optimum fiber lengths are disclosed.
Inventors
- 👤 J Stone
- 👤 G Walrafen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 16:01
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/62; G01N21/63; G01N21/65; G01N2021/651
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
89 words
A method of inducing and collecting Raman radiation comprising the steps of: directing a beam of excitation radiation onto an end of a liquid core optical fiber and guiding said beam therealong, where the fiber core comprises a solution of the Raman sample material, and the fiber cladding is a low-loss material having a lower refractive index than said sample material at both the wavelength of the excitation radiation, and the wavelength of the induced Raman radiation; and extracting the induced Raman radiation from an end of said fiber.
Claim 2
Independent Claim
89 words
A method of inducing and collecting Raman radiation comprising the steps of: directing a beam of excitation radiation onto an end of a liquid core optical fiber and guiding said beam therealong, where the fiber core comprises a solution of the Raman sample material, and the fiber cladding is a low-loss material having a lower refractive index than said sample material at both the wavelength of the excitation radiation, and the wavelength of the induced Raman radiation; and extracting the induced Raman radiation from an end of said fiber.
Claim 3
Dependent Claim
32 words
The method according to claim 1 wherein said excitation radiation is directed onto one end of said fiber; and wherein said Raman radiation is extracted from the other end of said fiber.
Claim 4
Dependent Claim
49 words
The method according to claim 1 wherein said excitation radiation is directed onto one end of said fiber; said Raman radiation is extracted from said same one end; and wherein the length of said fiber is greater than 1/2 Alpha where Alpha is the attenuation coefficient of said fiber.
Claim 5
Dependent Claim
15 words
The method according to claim 1 wherein said fiber is at least 20 centimeters long.
Claim 6
Dependent Claim
32 words
The method according to claim 1 where the length of said fiber L, is given by L 1/ Alpha where Alpha is the average attenuation coefficient over the frequency band of interest.
References Cited (Backward Citations)
US3556659A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-05 | 1977-05-07 | 1977-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-05 | 1981-05-07 | 1981-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-05 | 1985-05-07 | 1985-11-06 | $7700.00 | Window Closed / Lapsed |