Optical fiber manufacture
US6220060A · kind A · utility
7Cited by
1References
15Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 8, 1999 |
| Grant date | Apr 24, 2001 |
| Priority date | — |
| Expiry date | Apr 8, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P40/57
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
The specification describes a process and apparatus for collapsing preform tubes in Modified Chemical Vapor Deposition processes. The problem of bubble formation during tube collapse was found to be attributable to excess dopant vapor pressure emitted from the hot zone during the final stage of tube collapse. This excess pressure is controlled by cooling the tube in advance of the torch, thereby decreasing the viscosity of the dopant vapor and increasing its transport rate. This is found to reduce internal tube pressure and eliminate bubble formation in the collapsed preform.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.