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US4413882A Expired / Lapsed US ⏱️ 0.0 years remaining

Low viscosity core glass optical fiber

Assignee: Corning Glass Works
•
Filing: 1981-05-26
•
Granted: 1983-11-08
•
Expires: 2001-05-26
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Abstract

Abstract Solid glass articles are made by the flame hydrolysis technique. A thin stratum of low viscosity glass soot is applied to the surface of a mandrel. First and second coatings of glass soot are deposited on the surface of the thin stratum to form a porous preform. The refractive index of the soot particles of the first coating is greater than that of the soot of the second coating, and the soot of the first coating has a viscosity lower than that of the second coating. The mandrel is removed, and the soot preform is subjected to a high temperature whereby it is consolidated to form a dense glass blank. The glass surface tension and the relative viscosities of the inner and outer portions of the preform cause the aperture to close during the consolidation process. The thin stratum, which preferably includes P 2 O 5 , smoothes over the damage caused by removing the mandrel and reduces or even eliminates seed formation at the axis of the resultant glass blank. The blank is heated and drawn into an optical fiber.

Inventors

  • 👤 Alan C. Bailey
  • 👤 Alan J. Morrow

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 20:15
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/02; G02B6/036; G02B6/03605; G02B6/03611; C; C03; C03B; C03B37/00; C03B37/01; C03B37/012; C03B37/014; C03B37/01413; C03B37/01446; G02B6/028; G02B6/0281; C03B2201/00; C03B2201/02; C03B2201/06; C03B2201/20; C03B2201/28; C03B2201/30; C03B2201/31; C03B2203/00; C03B2203/10; C03B2203/22; C03B2207/00; C03B2207/80; C03B2207/85; C03B2207/87

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 118 words
An optical waveguide fiber comprising a glass core surrounded by a layer of cladding glass having a refractive index lower than that of said core, the viscosity V 1 of the core glass being less than the viscosity V 2 of the cladding glass, said fiber being characterized in that it further comprises an axial region of low viscosity glass within said core, the viscosity V 1 being greater than the viscosity V 3 of said axial region, said viscosities being determined at that temperature at which said cladding glass has a viscosity of 10 10 poise, there being an abrupt change in viscosity at the interface between said axial region and the remainder of said glass core.
Claim 2
Dependent Claim 118 words
An optical waveguide fiber comprising a glass core surrounded by a layer of cladding glass having a refractive index lower than that of said core, the viscosity V 1 of the core glass being less than the viscosity V 2 of the cladding glass, said fiber being characterized in that it further comprises an axial region of low viscosity glass within said core, the viscosity V 1 being greater than the viscosity V 3 of said axial region, said viscosities being determined at that temperature at which said cladding glass has a viscosity of 10 10 poise, there being an abrupt change in viscosity at the interface between said axial region and the remainder of said glass core.
Claim 3
Dependent Claim 24 words
An optical waveguide fiber in accordance with claim 1 wherein said axial region comprises at least 7 wt. % P 2 O 5 .
Claim 4
Dependent Claim 30 words
An optical waveguide fiber in accordance with claim 2 wherein said axial region and said core region comprises SiO 2 doped with GeO 2 and P 2 O 5 .
Claim 5
Dependent Claim 49 words
An optical waveguide fiber in accordance with claim 3 wherein the amount of GeO 2 in said axial region is less than the amount of P 2 O 5 therein and the amount of GeO 2 in said core region exceeds the amount of P 2 O 5 therein.
Claim 6
Dependent Claim 21 words
An optical waveguide fiber in accordance with claim 1 wherein the diameter of said axial region is less than 15 μm.
Claim 7
Dependent Claim 29 words
An optical waveguide fiber in accordance with claim 1 wherein the ratio of the diameter of said axial region to that of said core region is less than 1/3.
Claim 8
Dependent Claim 30 words
A fiber in accordance with claim 1 wherein said axial region is formed of a binary glass composition, at least 7 wt. % of which is said viscosity depressing oxide.
Claim 9
Dependent Claim 29 words
A fiber in accordance with claim 1 wherein the ratio V 1 /V 2 is less than 1/2 and the ratio V 3 /V 1 is less than 1/10.

References Cited (Backward Citations)

US4339173A Cited
US4111525A Cited
US4181403A Cited
US4358181A Cited
US4339174A Cited
US4344670A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1986-11-07 1987-05-09 1987-11-08 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1990-11-07 1991-05-09 1991-11-08 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1994-11-07 1995-05-09 1995-11-08 $7700.00 Window Closed / Lapsed

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