Method and apparatus for forming a tube-encased bragg grating
US6298184A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 4, 1998 |
| Grant date | Oct 2, 2001 |
| Priority date | — |
| Expiry date | Dec 4, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B2006/02161
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method and apparatus for forming a tube-encased fiber grating includes an optical fiber 28 which is encased within and fused to at least a portion of a glass capillary tube 120 and a substantially transparent index-matching medium 122, such as an optically flat window, having an optically flat surface 126 adjacent to the tube 120. A substantially transparent index-matching intermediate material (e.g., UV transparent oil) 124 is used between the window 22 and the tube 120 to substantially eliminate the interface between the tube 120 and the medium 122. A pair of writing beams 26,34 are incident on and pass through the medium 122, the tube 120 and intersect and interfere in a region 30 on the fiber 28. Also, the width Wb of the writing beams 26,34 may be set to be less than the width Woil of the intermediate material 124 to eliminate surface damage (ablations) of the tube 120. Attentively, the medium 122 may have a geometry to eliminate surface ablations (e.g., a collar shape) and/or to match the shape of the tube 120. More than one grating or pair of gratings may be written in the tube-encased fiber or one or more gratings may be formed in multiple fibers 28,250 encased in the tub…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.