Optical fiber with low fictive temperature
US10961145B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 20, 2017 |
| Grant date | Mar 30, 2021 |
| Priority date | — |
| Expiry date | Feb 12, 2038 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03B2205/44
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Optical fibers having low fictive temperature and methods of making such fibers are described. Management of the cooling rate of an optical fiber during fiber draw permits control over the fictive temperature of the fiber. Non-monotonic cooling rates are shown to promote reductions in fiber fictive temperature. The non-monotonic cooling includes slower cooling rates in upstream portions of the process pathway and faster cooling rates in downstream portions of the process pathway. Reduction in fiber fictive temperature is achieved by controlling the ambient temperature of the fiber to slow the cooling rate of the fiber in upstream portions of the process pathway that correspond to the fiber temperature regime in which the fiber viscosity is sufficiently low to permit efficient structural relaxation. Increases in cooling rate in downstream portions of the process pathway permit adjustment of fiber temperature as needed to meet entrance temperature requirements of downstream processing units. Lower fiber fictive temperature and lower fiber attenuation are achieved at faster draw speeds through non-monotonic cooling of fiber temperature.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.