Optical fiber having a bragg grating formed in its cladding
US6321007A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 24, 1999 |
| Grant date | Nov 20, 2001 |
| Priority date | — |
| Expiry date | Nov 24, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/03694
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A single mode optical fiber, having a pure silica core and a cladding, and having a Bragg grating in along a length of some of the cladding, providing reflectivity in some of the cladding but not in the core, and a method for making same. Because the core is pure silica, it is unaffected by exposure to ultraviolet light, and so the process of imprinting a Bragg grating does not affect the refractive index of the core. The portion of the cladding in which the Bragg grating is to be imprinted is a glass containing an index-lowering dopant, such as fluorine, as well as a photosensitizing dopant, such as germanium. Exposure to ultraviolet light therefore forms a Bragg grating in a portion of the cladding, but not in the core, providing reflectivity in the cladding, but not in the core. A second portion of cladding can also be provided, surrounding the portion doped with the photosensitizing dopant. The second portion of cladding is an outer cladding, surrounding the doped portion, which abuts the core.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.