US4519826A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical fibers having a fluoride glass cladding and method of making
Assignee: United States Department of the Navy
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Filing: 1983-04-14
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Granted: 1985-05-28
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Expires: 2003-04-14
Abstract
Abstract Fluoride glass cladded optical fibers are produced by rotationally casting a fluoride glass cladding tube, introducing core glass melt therein to form a preform, and drawing the preform into a fiber. Disclosed are methods whereby the process may be adopted to the production of multimode, stepped index profile waveguides, single mode waveguides, and waveguides having parabolic index profiles.
Inventors
- 👤 Danh C. Tran
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 13:34
CPC Classifications
C; C03; C03B; C03B19/00; C03B19/04; C03B37/00; C03B37/01; C03B37/012; C03B37/01265; C03B37/01268; C03B2201/00; C03B2201/80; C03B2201/82; Y; Y10; Y10S; Y10S65/00; Y10S65/15; Y10S65/16
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
137 words
A method of forming an optical fiber having a core and fluoride glass cladding comprising the steps of: axially rotating a vertically-disposed, thermally-conductive tubular mold containing a fluoride glass cladding melt until said cladding melt has coated essentially the entire bore surface of said mold; rapidly tilting the mold, while continuing to axially rotate said mold, until said mold becomes horizontally disposed; continuing to axially rotate said mold at least until said cladding melt has evenly coated the bore surface of said mold; rapidly cooling said cladding melt until its temperature is about equal to that of said mold, thus forming a cladding tube; introducing a glass core melt suitable for producing optical fibers into said cladding tube to form a preform; removing said preform from said mold; and drawing said preform to form an optical fiber.
Claim 2
Independent Claim
137 words
A method of forming an optical fiber having a core and fluoride glass cladding comprising the steps of: axially rotating a vertically-disposed, thermally-conductive tubular mold containing a fluoride glass cladding melt until said cladding melt has coated essentially the entire bore surface of said mold; rapidly tilting the mold, while continuing to axially rotate said mold, until said mold becomes horizontally disposed; continuing to axially rotate said mold at least until said cladding melt has evenly coated the bore surface of said mold; rapidly cooling said cladding melt until its temperature is about equal to that of said mold, thus forming a cladding tube; introducing a glass core melt suitable for producing optical fibers into said cladding tube to form a preform; removing said preform from said mold; and drawing said preform to form an optical fiber.
Claim 3
Dependent Claim
35 words
The method of claim 1 wherein the step of introducing a core melt into said cladding tube comprises the step of introducing a core melt consisting essentially of fluoride glass melt into said cladding tube.
Claim 4
Dependent Claim
17 words
The method of claim 2 wherein said core melt is introduced into said cladding tube by suction.
Claim 5
Dependent Claim
18 words
The method of claim 2 wherein said core melt is introduced into said cladding tube by positive pressure.
Claim 6
Dependent Claim
31 words
The method of claim 2 wherein successive layers of said core melt are introduced into said cladding tube by spraying said core melt along the inside surface of said cladding tube.
Claim 7
Dependent Claim
13 words
The method of claim 2 wherein said mold rotates at about 2000-5000 rpm.
Claim 8
Dependent Claim
13 words
The method of claim 6 wherein said mold rotates at about 2000-3500 rpm.
Claim 9
Dependent Claim
31 words
The method of claim 1 further comprising the step of preparing said fluoride glass cladding melt by melting the raw material for said fluoride glass melt directly in said rotating mold.
Claim 10
Dependent Claim
33 words
The method of claim 1 further comprising the step of heating said mold to about 50° C. below the transition temperature of said cladding melt before introducing said cladding melt into said mold.
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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) | 1988-05-27 | 1988-11-26 | 1989-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-05-27 | 1992-11-26 | 1993-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-05-27 | 1996-11-26 | 1997-05-28 | $7700.00 | Window Closed / Lapsed |