Method of making fluorine/boron doped silica tubes
US5203898A · kind A · utility
26Cited by
5References
14Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 16, 1991 |
| Grant date | Apr 20, 1993 |
| Priority date | — |
| Expiry date | Dec 16, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S65/16
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Disclosed is a method of forming a glass tube doped with boron and fluorine. A B.sub.2 O.sub.3 -doped tubular porous preform is heated, and a fluorine-containing gas is flowed into its aperture. The temperature is sufficiently high to cause the fluorine-containing gas to decompose and form fluorine which dopes the preform. Also flowed into the aperture is a sufficient amount of BF.sub.3 to prevent fluorine from reacting with the B.sub.2 O.sub.3 in the porous preform and forming a B.sub.2 O.sub.3 -depleted region near the aperture surface. The particles are then fused to form a fluorine-containing dense glass tube.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.