EP0249230A1
Expired / Lapsed
EP
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Glass preform for dispersion shifted single mode optical fiber and method for the production of the same
Assignee: Sumitomo Electric Industries Ltd
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Filing: 1987-06-11
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Granted: —
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Expires: 2007-06-11
Abstract
Abstract A glass preform for use in the fabrication of a dispersion shifted single mode optical fiber is produced by a method for comprising steps of inserting a core member consisting of an inner core part made of a germanium-added quartz glass which optionally contains fluorine and an outer core part made of a quartz glass having a refractive index smaller than that of the inner core part in a glass tube made of a fluorine-added quartz glass having a refractive index smaller than that of the outer core part, heating the core member and the glass tube to collapse the glass tube and fuse them together to produce a glass preform, and a glass preform comprising a core member consisting of an inner core part made of GeO₂-SiO₂ glass or GeO₂-F-SiO₂ glass and an outer core part made of F-SiO₂ glass and a cladding made of F-SiO₂ glass provides a dispersion shifted single mode optical fiber having reduced attenuation of light transmission in the 1.5 µm wavelength band.
Inventors
- 👤 Hiroo C/O Yokohama Works Kanamori
- 👤 Hiroshi C/O Yokohama Works Yokota
- 👤 Gotaro C/O Yokohama Works Tanaka
- 👤 Yoichi C/O Yokohama Works Ishiguro
- 👤 Masahiro C/O Yokohama Works Takagi
- 👤 Hiroshi C/O Yokohama Works Suganuma
- 👤 Masayuki C/O Yokohama Works Shigematsu
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 10:26
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/02; G02B6/02214; G02B6/02219; G02B6/02276; C; C03; C03B; C03B37/00; C03B37/01; C03B37/012; C03B37/01205; C03B37/01211; C03B37/014; C03B37/01446; C03B37/01466; C03B37/10; C03B37/12; C03C; C03C13/00; C03C13/04; C03C13/045; G02B6/036; G02B6/03616; G02B6/03622; G02B6/03633; C03B2201/00; C03B2201/06; C03B2201/08; C03B2201/12; C03B2203/00; C03B2203/10; C03B2203/22; C03B2203/36; Y; Y10; Y10S; Y10S65/00; Y10S65/15; Y10S65/16; Y10S65/90
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
109 words
A method for producing a glass preform for use in the fabrication of a dispersion shifted single mode optical fiber comprising steps of inserting a core member consisting of an inner core part made of a germanium-added quartz glass which optionally contains fluorine and an outer core part made of a quartz glass having a refractive index smaller than that of the inner core part in a glass tube made of a fluorine-added quartz glass having a refractive index smaller than that of the outer core part, heating the core member and the glass tube to collapse the glass tube and fuse them together to produce a glass preform.
Claim 2
Independent Claim
109 words
A method for producing a glass preform for use in the fabrication of a dispersion shifted single mode optical fiber comprising steps of inserting a core member consisting of an inner core part made of a germanium-added quartz glass which optionally contains fluorine and an outer core part made of a quartz glass having a refractive index smaller than that of the inner core part in a glass tube made of a fluorine-added quartz glass having a refractive index smaller than that of the outer core part, heating the core member and the glass tube to collapse the glass tube and fuse them together to produce a glass preform.
Claim 3
Dependent Claim
70 words
The method according to claim 1, wherein the core member is produced by a VAD method comprising synthesizing glass soot particles by flame hydrolysis of a glass forming raw material, depositing the glass soot particles on a starting member to produce a porous glass body, dehydrating the porous glass body, optionally adding fluorine to the porous glass body, and sintering the porous glass body to obtain the transparent core member.
Claim 4
Dependent Claim
17 words
The method according to claim 2, wherein the dehydration and addition of fluorine are carried out simultaneously.
Claim 5
Dependent Claim
23 words
The method according to claim 2, wherein the sintering of the glass body is carried out in an atmosphere containing a fluorine-containing compound.
Claim 6
Dependent Claim
55 words
The method according to claim 1, wherein the core member is produced by a rod-in-tube method comprising inserting a glass rod for an inner core part rod in a glass tube for an outer glass tube, heating them and shrinking the glass tube to integrate it with the glass rod to obtain the core member.
Claim 7
Dependent Claim
49 words
A glass preform for use in the fabrication of a dispersion shifted single mode optical fiber comprising a core member consisting of an inner core part made of GeO₂-SiO₂ glass or GeO₂-F-SiO₂ glass and an outer core part made of F-SiO₂ glass, and a cladding made of F-SiO₂ glass.
Claim 8
Dependent Claim
49 words
A glass preform for use in the fabrication of a dispersion shifted single mode optical fiber comprising a core member consisting of an inner core part made of GeO₂-SiO₂ glass or GeO₂-F-SiO₂ glass and an outer core part made of F-SiO₂ glass, and a cladding made of F-SiO₂ glass.
Claim 9
Dependent Claim
29 words
The glass preform according to claim 6, wherein the core member consists the inner core part made of GeO₂-SiO₂ glass and the outer core part made of F-SiO₂ glass.
Claim 10
Dependent Claim
30 words
The glass preform according to claim 6, wherein the core member consists of the inner core part made of GeO₂-F-SiO₂ glass and the outer core part made of F-SiO₂ glass.
References Cited (Backward Citations)
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