EP0151438A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method for producing glass preform for optical fiber
Assignee: Sumitomo Electric Industries Ltd
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Filing: 1985-01-24
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Granted: —
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Expires: 2005-01-24
Abstract
Abstract Fluorine is selectively added to a cladding portion of a glass preform by producing a soot preform which comprises a core portion (9) and a cladding portion (10) under such conditions that an additive concentration or a bulk density of the outermost part (11 B) of the core portion (9) is to be larger than that of the inner part thereof and heating the soot preform in an atmosphere containing fluorine or a fluorine-containing compound at least in some period to obtain a transparent glass preform.
Inventors
- 👤 Hiroshi C/O Yokohama Works Of Sumitomo Kawauchi
- 👤 Michihisa C/O Yokohama Works Of Sumitomo Kyoto
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 00:12
CPC Classifications
C; C03; C03B; C03B37/00; C03B37/10; C03B37/12; C03C; C03C13/00; C03C13/04; C03C13/045; C03B37/01; C03B37/012; C03B37/014; C03B37/01413; C03B37/0142; C03B37/01446; C03B2201/00; C03B2201/06; C03B2201/08; C03B2201/12; C03B2203/00; C03B2203/10; C03B2203/22; C03B2207/00; C03B2207/36; Y; Y10; Y10S; Y10S65/00; Y10S65/15; Y10S65/16
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
83 words
A method for producing a glass preform, characterised by producing a soot preform which comprises a core portion (9) and a cladding portion (10) under such conditions that an additive concentration or a bulk density of the outermost part (11B) of the core portion (9) is to be larger than that of the inner part thereof and heating the soot preform (9, 10) in an atmosphere containing fluorine or a fluorine-containing compound at least in some period to obtain a transparent glass preform.
Claim 2
Independent Claim
83 words
A method for producing a glass preform, characterised by producing a soot preform which comprises a core portion (9) and a cladding portion (10) under such conditions that an additive concentration or a bulk density of the outermost part (11B) of the core portion (9) is to be larger than that of the inner part thereof and heating the soot preform (9, 10) in an atmosphere containing fluorine or a fluorine-containing compound at least in some period to obtain a transparent glass preform.
Claim 3
Dependent Claim
26 words
A method according to claim 1 characterised in that before heating, the soot preform is heated in an atmosphere containing a chlorine-containing compound to dehydrate it.
Claim 4
Dependent Claim
23 words
A method according to claim 1 or 2 characterised in that the soot preform is heated at a temperature of 1,000 to 1,300°C.
Claim 5
Independent Claim
54 words
A method according to any one of claims 1 to 3 characterised in that the soot preform is produced under such condition that both the additive concentration and the bulk density of the outermost part (11B) of the core portion (9) are larger than those of the inner part of the core portion (9).
References Cited (Backward Citations)
No citation records indexed.
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