Patent US4289516A successfully refreshed from Google Patents.
US4289516A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low loss optical fibers
Assignee: 3M Fiber Optic Products Inc
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Filing: 1979-10-04
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Granted: 1981-09-15
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Expires: 1999-10-04
Abstract
Abstract A method is provided for making an optical fiber by melting and cladding a multi-component core glass without adding the contamination that is normally associated with these processes. As an initial step, a pure multi-component glass is melted in a high purity silica crucible. The temperature of the glass in the crucible and the temperature of the orifice thereof are controlled so that a cane of glass is drawn from the bottom of the crucible. This cane of glass is fed into a silica or borosilicate tube which is being drawn into a fiber. This results in an optical fiber in which the multi-component glass forms the core while the tube forms the cladding.
Inventors
- 👤 David A. Krohn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 14:16
CPC Classifications
C; C03; C03B; C03B37/00; C03B37/01; C03B37/02; C03B37/025; C03B37/027; C03B37/02754; C03B37/022; C03B37/023; C03C; C03C13/00; C03C13/04; C03C13/045; C03C13/046; C03B2201/00; C03B2201/06; C03B2201/08; C03B2201/10; C03B2201/30; C03B2201/50; C03B2201/54; C03B2205/00; C03B2205/12; C03B2205/14; C03B2205/16
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
121 words
A process for making an optical fiber, said process utilizing a crucible having a bottom with an orifice therein, said process comprising the step of: melting a core material having a first refractive index; drawing a cane of said core material from said aperture and through the interior of a tube composed of cladding material having a refractive index less than the refractive index of said batch material; and drawing one end of said tube simultaneously with said cane so that an optical fiber is formed having a core composed of said core material and a cladding composed of said cladding material, said drawn tube end being heated sufficiently to cause said cane and said tube to fuse at their interface.
Claim 2
Dependent Claim
121 words
A process for making an optical fiber, said process utilizing a crucible having a bottom with an orifice therein, said process comprising the step of: melting a core material having a first refractive index; drawing a cane of said core material from said aperture and through the interior of a tube composed of cladding material having a refractive index less than the refractive index of said batch material; and drawing one end of said tube simultaneously with said cane so that an optical fiber is formed having a core composed of said core material and a cladding composed of said cladding material, said drawn tube end being heated sufficiently to cause said cane and said tube to fuse at their interface.
Claim 3
Dependent Claim
22 words
The process of claim 1 wherein said core material is a multi-component glass and said crucible is made of high purity silica.
Claim 4
Dependent Claim
16 words
The process of claim 1 wherein said tube is made of one of silica and borosilicate.
Claim 5
Dependent Claim
24 words
The process of claim 1 wherein said crucible is maintained at a temperature in the range of 1,000 degrees C. to 1,500 degrees C.
Claim 6
Dependent Claim
29 words
The process of claim 1 wherein the portion of said tube being drawn is maintained at a temperature in the range of 1,800 degrees C. to 2,000 degrees C.
Claim 7
Dependent Claim
29 words
The process of claim 1 wherein the portion of said tube being drawn is maintained at a temperature in the range of 1,000 degrees C. to 1,200 degrees C.
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) | 1984-09-14 | 1985-03-16 | 1985-09-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-09-14 | 1989-03-16 | 1989-09-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-09-14 | 1993-03-16 | 1993-09-15 | $7700.00 | Window Closed / Lapsed |