Multi-mode fiber coupler, system and associated methods
US6530697B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 11, 1999 |
| Grant date | Mar 11, 2003 |
| Priority date | — |
| Expiry date | Jun 11, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/4214
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An optical coupler reduces differential mode delay in a fiber by reducing an amount of light incident on the fiber in a region in which the refractive index is not well controlled. This region of the fiber is typically in the center of the fiber. The optical coupler directs light away from the this region and/or provides a high angle of incidence to any light on this region. A diffuser may be used to reduce sensitivity of the coupler to any fluctutations in the output of the light source. The optical coupler does not need to be offset from the center of the multi-mode coupler. A phase function of an azimuthal mode of the fiber may be imposed on the light beam so that a substantial null on axis is maintained even after propogation of the light beam beyond the depth of focus of the coupler. A diffractive element generating a beam which propogates in a spiral fashion along an axis allows the shape of the beam to be maintained for longer than a depth of focus of the diffractive element.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.