Methods of fabricating grating assisted coupler devices
US6465153B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 31, 2000 |
| Grant date | Oct 15, 2002 |
| Priority date | — |
| Expiry date | Feb 16, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/2835
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Advantageous methodologies are disclosed for embedding periodic patterns in optical waveguide elements such as optical fibers. Polarization independence in an elongated waist region of a coupler can be established by measuring polarization characteristics during fusion and elongation, and controlling the heating and stretching to impart a cross-sectional shape, such as a hybrid dumbbell-ellipsoid produces a polarization insensitive drop wavelength. Alternatively, or additionally, polarization dependence can be minimized by angular deformation of the elements along its light transmissive axis. In addition, an element of relatively low photosensitivity is held in an hydrogen or deuterium environment pressurized to about 1000 to 5000 psi. While the environment is pressurized, a scanning UV beam is transmitted through a photomask and impinges on the coupler waist. In writing the grating, the in-diffused gas is constantly replenished, enabling the grating to grow. Prior to writing the periodic pattern dimensional variations in the element which can affect spectral bandwidth are sensed by writing a test pattern in the element and then locally measuring the spectral properties of the test…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.