Increasing a fluorine compound flow rate during a VAD process
US5895515A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 22, 1996 |
| Grant date | Apr 20, 1999 |
| Priority date | — |
| Expiry date | Nov 22, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/0365
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
In a soot-deposition container, raw material gas and at the tip of a starting glass rod, combustion gas, and carrier gas are supplied to a core-depositing burner and raw material gas, combustion gas, carrier gas, and gas for doping of fluorine are supplied to a cladding-depositing burner, thereby forming porous glass soot comprised of glass soot for core and glass soot for cladding. With growth of soot, the supply amount of the fluorine-doping gas is increased while supply amounts of the other gases are kept constant. Next, dehydration process and transparentizing process of soot are carried out to obtain a glass preform for optical fiber. Fabricated in this way is the glass preform for optical fiber having the silica glass portion doped with low-concentration fluorine with high uniformity in the growth direction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.