Method of making a tubular member for optical fiber production using plasma outside vapor deposition
US6253580A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 19, 1997 |
| Grant date | Jul 3, 2001 |
| Priority date | — |
| Expiry date | Dec 19, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03B2201/12
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An apparatus and method for producing a tubular member, which is suitable for use as a starter tube or an optical fiber preform, on a rotating cylindrical target mounted on a lathe. The tubular member is made by means of plasma outside vapor deposition. In this process, a source gas comprising SiCl.sub.4 and, optionally, a fluorine-laden chemical, is introduced into an air plasma. Both the air and the source gas are dry gases and have low hydroxyl content. The air plasma is created by a high-frequency induction plasma torch which travels along the length of the target on a carriage. The torch is provided with a short U-shaped gutter on either side of its rim directly beneath the target and the growing tubular member. This gutter helps channel reaction products of the source gas and the plasma so as to enhance deposition on the growing tubular member. The torch is further provided with an induction coil having a plurality of windings, the uppermost winding being maintained a predetermined distance from the surface of the tubular member as the latter is built up.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.