Method for manufacturing a glass core preform for optical fibres
US10934205B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 9, 2015 |
| Grant date | Mar 2, 2021 |
| Priority date | — |
| Expiry date | Nov 9, 2035 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03B2203/22
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A method of manufacturing a glass core preform for optical fibres including providing a porous soot core preform having a central longitudinal hole extending axially therethrough and an a/b ratio of from 0.20 to 0.40; simultaneously dehydrating and doping with fluorine the soot core preform at a temperature of from 1000° C. to 1350° C. by exposing it to an atmosphere containing a chlorine-containing gas and a fluorine-containing gas, the content of the fluorine-containing gas in the atmosphere being of from 0.01% to 0.50% by volume, and simultaneously consolidating the soot core preform and closing the central longitudinal hole by exposing the soot core preform to an atmosphere substantially devoid of fluorine and of chlorine at a consolidation temperature of from 1500° C. to 1650° C., while reducing the pressure down the central hole, thereby forming a glass core preform.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.