Method of making optical fiber having depressed index core region
US5917109A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 5, 1997 |
| Grant date | Jun 29, 1999 |
| Priority date | — |
| Expiry date | Feb 5, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/0281
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Disclosed is a method of making an optical fiber preform having at least one annular region of depressed refractive index. A tube of silica doped with fluorine and/or boron is overclad with silica soot. A core rod is inserted into the overclad tube and the resultant assembly is heated while chlorine flows between the tube and the core rod to clean the adjacent surfaces. When the soot sinters, the tube collapses onto and fuses to the rod. The resultant tubular structure is formed into an optical fiber which exhibits low attenuation as a result of the low seed count at the interface between the inner core and the region that is doped with fluorine and/or boron.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.