Patent US4423925A successfully refreshed from Google Patents.
US4423925A
Expired / Lapsed
US
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Graded optical waveguides
Assignee: Times Fiber Communications Inc
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Filing: 1981-07-28
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Granted: 1984-01-03
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Expires: 2001-07-28
Abstract
Abstract A process for preparing a glass rod having a graded refractive index for use as the start rod in the production of optical waveguides is disclosed. The process comprises depositing and sintering borosilicate particles on a glass rod to form a rod having a larger diameter than the original fused silica rod and drawing this rod to obtain a start rod having the same diameter as the original glass rod but exhibiting a partially radially graded refractive index. Optical waveguides prepared from such graded start rods have a more uniformly graded radial index of refraction profile.
Inventors
- 👤 Franklin W. Dabby
- 👤 Ronald B. Chesler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:52
CPC Classifications
C; C03; C03B; C03B37/00; C03B37/01; C03B37/012; C03B37/01205; C03B37/014; C03B37/01466; C03B37/01486; C03B37/01493; C03B2201/00; C03B2201/06; C03B2201/08; C03B2201/10; C03B2203/00; C03B2203/10; C03B2203/22; C03B2203/24
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
72 words
An optical waveguide comprising (i) a core comprised of a central area of pure fused silica of constant refractive index and an outer region of borosilicate exhibiting a radially decreasing refractive index and (ii) a cladding of borosilicate of constant refractive index, lower than the refractive indices present in said core, characterized in that said central area of constant refractive index comprises less than 10% of the cross-sectional area of said waveguide.
Claim 2
Dependent Claim
72 words
An optical waveguide comprising (i) a core comprised of a central area of pure fused silica of constant refractive index and an outer region of borosilicate exhibiting a radially decreasing refractive index and (ii) a cladding of borosilicate of constant refractive index, lower than the refractive indices present in said core, characterized in that said central area of constant refractive index comprises less than 10% of the cross-sectional area of said waveguide.
Claim 3
Dependent Claim
26 words
The optical waveguide as defined by claim 1, wherein the ratio of boron oxide to silica in said cladding increases with radial distance from said core.
Claim 4
Dependent Claim
32 words
The optical waveguide as defined by claim 1, wherein the ratio of boron oxide to silica varies from zero at the center of the waveguide to approximately 3 at the circumference thereof.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-01-02 | 1987-07-04 | 1988-01-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-01-02 | 1991-07-04 | 1992-01-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-01-02 | 1995-07-04 | 1996-01-03 | $7700.00 | Window Closed / Lapsed |