Patent US5059229A successfully refreshed from Google Patents.
US5059229A
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Method for producing optical fiber in a hydrogen atmosphere to prevent attenuation
Assignee: Corning Inc
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Filing: 1990-09-24
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Granted: 1991-10-22
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Expires: 2010-09-24
Abstract
Abstract An optical fiber is drawn from a draw blank that is situated in a furnace muffle. An end of the blank is heated to a temperature sufficient to permit a fiber to be drawn therefrom. During the fiber drawing operation, the blank is subjected to a gas containing an amount of hydrogen sufficient to reduce the number of defects in the fiber. The resultant fiber therefore experiences little or no latent attenuation increase when it is later subjected to a hydrogen containing atmosphere.
Inventors
- 👤 Michael G. Blankenship
- 👤 George E. Berkey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 05:31
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/02; C; C03; C03B; C03B37/00; C03B37/01; C03B37/02; C03B37/025; C03B37/029; C03C; C03C25/00; C03C25/60; C03C25/607; G02B6/44; G02B6/4401; G02B6/4429; G02B6/44382; C03B2205/00; C03B2205/60; C03B2205/62; C03B2205/64; C03B2205/80; C03B2205/82; C03B2205/83; G02B6/036; G02B6/03616; G02B6/03661; Y; Y02; Y02P; Y02P40/00; Y02P40/50; Y02P40/57
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
137 words
A method of manufacturing a silica based optical fiber that is protected at least partially from latent attenuation increase due to hydrogen comprising drawing said optical fiber from a draw blank while a hydrogen (H 2 )-containing gas is present in the draw furnace, a tapered root forming a transition between said draw blank and said fiber, said gas flowing over said root and over that portion of said fiber adjacent said root and being exhausted from said furnace, whereby that portion of said fiber over which said gas flows is subjected to draw temperature, said fiber being pulled from an end of said furnace, said gas containing an amount of hydrogen sufficient to form an optical fiber that exhibits an attenuation of less than 8 db/km at 630 nm at the time that it is drawn.
Claim 2
Independent Claim
137 words
A method of manufacturing a silica based optical fiber that is protected at least partially from latent attenuation increase due to hydrogen comprising drawing said optical fiber from a draw blank while a hydrogen (H 2 )-containing gas is present in the draw furnace, a tapered root forming a transition between said draw blank and said fiber, said gas flowing over said root and over that portion of said fiber adjacent said root and being exhausted from said furnace, whereby that portion of said fiber over which said gas flows is subjected to draw temperature, said fiber being pulled from an end of said furnace, said gas containing an amount of hydrogen sufficient to form an optical fiber that exhibits an attenuation of less than 8 db/km at 630 nm at the time that it is drawn.
Claim 3
Dependent Claim
16 words
A method in accordance with claim 1 wherein the major constituent of said gas is helium.
Claim 4
Dependent Claim
15 words
A method in accordance with claim 2 which said gas consists of helium and hydrogen.
Claim 5
Dependent Claim
31 words
A method in accordance with claim 1 wherein said gas comprises a mixture of hydrogen and another gas selected from the group consisting of argon, helium, oxygen, air and mixtures thereof.
Claim 6
Dependent Claim
55 words
A method in accordance with claim 1 wherein said gas flows into said furnace at that end of said draw blank opposite that from which said fiber exits as it is drawn, said gas flowing over said draw blank, over the root between said draw blank and fiber, over said fiber, and from said furnace.
Claim 7
Dependent Claim
51 words
A method in accordance with claim 5 wherein said gas further flows from that end of said furnace from which said fiber exits and thereafter flows over said fiber as said fiber passes through a heated tubular member affixed to that end of said furnace from which said fiber is drawn.
Claim 8
Dependent Claim
18 words
A method in accordance with claim 1 wherein said gas consists essentially of an inert gas and hydrogen.
Claim 9
Independent Claim
167 words
A method of manufacturing silicate optical fibers comprising the steps of heating a draw blank in a draw furnace to the fiber drawing temperature, said draw blank having a silicate core glass region and a silicate cladding glass region, one of said core and cladding regions containing a dopant which causes the refractive index of the core region to exceed that of the cladding region, drawing said draw blank to reduce the diameter thereof and to form an optical fiber, a portion of said optical fiber and neckdown region between said fiber and said draw blank being situated in said furnace, subjecting said draw blank, said neckdown region and said portion of said optical fiber to a gas containing an amount of hydrogen (H 2 ) sufficient to form an optical fiber that exhibits an attenuation of less than 8 db/km at 630 nm at the time that it is drawn, whereby that portion of said fiber over which said gas flows is subjected to draw temperature.
Claim 10
Independent Claim
167 words
A method of manufacturing silicate optical fibers comprising the steps of heating a draw blank in a draw furnace to the fiber drawing temperature, said draw blank having a silicate core glass region and a silicate cladding glass region, one of said core and cladding regions containing a dopant which causes the refractive index of the core region to exceed that of the cladding region, drawing said draw blank to reduce the diameter thereof and to form an optical fiber, a portion of said optical fiber and neckdown region between said fiber and said draw blank being situated in said furnace, subjecting said draw blank, said neckdown region and said portion of said optical fiber to a gas containing an amount of hydrogen (H 2 ) sufficient to form an optical fiber that exhibits an attenuation of less than 8 db/km at 630 nm at the time that it is drawn, whereby that portion of said fiber over which said gas flows is subjected to draw temperature.
Claim 11
Dependent Claim
17 words
A method in accordance with claim 8 wherein said gas contains up to 12 volume percent hydrogen.
Claim 12
Dependent Claim
38 words
A method in accordance with claim 8 wherein said gas contains up to 100 percent hydrogen, said method further comprising the step of exhausting said gas from said furnace and preventing the flow of air into said furnace.
Claim 13
Dependent Claim
16 words
A method in accordance with claim 8 wherein the major constituent of said gas is helium.
Claim 14
Dependent Claim
15 words
A method in accordance with claim 8 which said gas consists of helium and hydrogen.
Claim 15
Dependent Claim
17 words
A method in accordance with claim 7 wherein said gas comprises at least 0.1 volume percent hydrogen.
Claim 16
Dependent Claim
23 words
A method in accordance with claim 7 wherein said gas flows from that end of said furnace from which said fiber is drawn.
Claim 17
Dependent Claim
18 words
A method in accordance with claim 7 wherein said gas consists essentially of an inert gas and hydrogen.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1994-10-21 | 1995-04-22 | 1995-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-10-21 | 1999-04-22 | 1999-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-10-21 | 2003-04-22 | 2003-10-22 | $7700.00 | Window Closed / Lapsed |