Optical fiber gratings having internal gap cladding for reduced short wavelength cladding mode loss
US6415079B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 3, 2000 |
| Grant date | Jul 2, 2002 |
| Priority date | — |
| Expiry date | Mar 3, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/29394
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The present invention is predicated on applicants' discovery that an appropriately spaced and dimensioned internal gap cladding can substantially reduce short wavelength cladding mode loss in a fiber Bragg grating. A fiber Bragg grating is provided with a ring of closely spaced, longitudinally extending gap regions in the glass peripherally surrounding the core. The gaps are spaced apart by thin glass webs having a thickness less than a wavelength of the light being transmitted and are disposed peripherally about the core at a distance of 2-10 wavelengths from the core center. The thin webs limit the passage of the light between the gaps. The combination of webs and gaps acts as an internal thin cladding which supports fewer cladding modes than conventional glass cladding and, significantly, provides increased wavelength spacing between the Bragg resonance and the first cladding mode resonance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.