Large mode area fiber for low-loss transmission and amplification of single mode lasers
US7283714B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 15, 2006 |
| Grant date | Oct 16, 2007 |
| Priority date | — |
| Expiry date | Dec 15, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S3/1618
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A large mode area optical fiber includes a large diameter core (d1 up to 60 μm), and a first cladding (diameter d2) wherein the difference between refractive index (n1) in the core and the first cladding (n2) is very small (Δn<0.002), thus providing a very low numerical aperture core (NA1 between 0.02 and 0.06). The preferred ratio of d2/d1<2. The fiber further has a second cladding, preferably a layer of air holes, having a very low refractive index n3 as compared to the core and first cladding such that the first cladding has a relatively high numerical aperture (NA2>0.4) (n3 is preferably less than 1.3). The small change in refractive index between the core and inner cladding combined with a large change in refractive index between the first cladding and second cladding provides a significantly improved single mode holding waveguide.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.