Method of making solid preforms and optical fibers drawn therefrom
US4341441A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 24, 1977 |
| Grant date | Jul 27, 1982 |
| Priority date | — |
| Expiry date | Jan 24, 1997 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03B2205/16
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An optical glass fiber is formed of an inner layer of germania doped glass within the bore of the outer cladding tube of silica. The tube with the higher index of refraction inner layer is rotated while being heated to collapse the bore to form an optical fiber preform. The preform is then drawn into fiber in a separate operation. A first silica layer can be deposited within the tube bore before the germania doped layer. The deposition of germania takes place under hydrogen free conditions. Appropriate heat treatment of the tube avoids excessive evaporation of germania and provides a graded transition of the refractive index in the boundary between core and cladding.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.