Continuous production of synthetic silica doped with fluorine
US4221825A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 18, 1979 |
| Grant date | Sep 9, 1980 |
| Priority date | — |
| Expiry date | Jul 18, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S65/16
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
The present invention relates to a process for the continuous manufacture of vitreous synthetic silica doped with fluorine. This process consists of decomposing a silicon compound free of hydrogen in the flame of an inductive plasma burner, thereby forming silica upon reacting with the oxygen contained in the burner feed gas. A gaseous inorganic fluorine compound free of hydrogen, is sent into the flame preferably from outside the burner. Said fluorine compound simultaneously with the silicon compound decomposes whereby fluorine is introduced into the silica, lowering its index of refraction. The doped silica is then deposited on a heat-stable support in the form of a vitreous mass. The doped synthetic silica is particularly useful for making preforms for optical transmission fibers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.