Hole assisted optical fiber
US11860405B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 18, 2019 |
| Grant date | Jan 2, 2024 |
| Priority date | — |
| Expiry date | Sep 24, 2039 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/036
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An object of the present invention is to provide an HAF having a structure in which the number of air holes is decreased to be smaller than that of a PCF and Rayleigh scattering loss may be more reduced than that in the existing HAF. The HAF according to the present invention includes a core portion having a uniform optical refractive index; a cladding portion having a uniform optical refractive index and surrounding the core portion; and a plurality of air holes arranged in two layers at positions configuring hexagonal closest packing excluding the core portion within the cladding portion along a longitudinal direction of the hole-assisted fiber, wherein a center-to-center spacing of the air holes is a sum of a radius Rin of an inscribed circle inscribed in the air holes in an inner layer and a radius d/2 of the air hole, and a radius “a” of the core portion and a relative refractive index difference Δ between the core portion and the cladding portion are present within a range where Rn, which is a ratio of a Rayleigh scattering coefficient Rsmf of a single mode optical fiber and an effective Rayleigh scattering coefficient Reff of the hole-assisted fiber, is equal to or less than…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.