Methods for producing optical fiber preforms with low index trenches
US9873629B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 30, 2011 |
| Grant date | Jan 23, 2018 |
| Priority date | — |
| Expiry date | May 19, 2032 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03B2207/70
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Methods for forming optical fiber preforms with low-index trenches are disclosed. According to one embodiment, the method includes depositing silica-based glass soot on a bait rod to form a low-index trench region of the optical fiber preform. The silica-based glass soot is deposited such that the low-index trench region has a first density. Thereafter a barrier layer having a second density greater than the first density is formed around the low-index trench region. Therafter, an overclad region is deposited around the barrier layer. The bait rod is then removed from a central channel of the trench-overclad assembly. A separate core assembly is inserted into the central channel. A down-dopant gas is then directed through the central channel of the trench-overclad assembly as the trench-overclad assembly is heated to dope the low-index trench region. The barrier layer prevents diffusion of the down-dopant from the low-index trench region into the overclad region.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.