Optical fiber coupler with low loss and high coupling coefficient and method of fabrication thereof
US7308173B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 18, 2004 |
| Grant date | Dec 11, 2007 |
| Priority date | — |
| Expiry date | Sep 3, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/2843
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An optical fiber coupler capable of providing a low loss, high coupling coefficient interface between conventional optical fibers and optical waveguide devices is provided. The novel coupler, which may be polarization maintaining, if a polarization maintaining preform is used in its fabrication includes a core, a cladding, a first end for interfacing with an optical fiber and a second end for interfacing with an optical waveguide device. The sizes of the core and cladding are gradually reduced from the first end to the second end in accordance with a predetermined reduction profile. Various parameters, such as refractive indices and sizes of the core and cladding and the reduction profile are selected to produce a low numerical aperture at the first end and a high numerical aperture at the second end, while advantageously minimizing insertion loss and maximizing the coupling coefficient at each end. In another embodiment, the novel coupler includes a secondary cladding which is also reduced between the first and second ends to improve the strength of the coupler structure at the second end. In yet another embodiment, one or two novel couplers are formed along with a chiral fiber ba…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.