Embodying amplitude information into phase masks
US6751381B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 24, 2002 |
| Grant date | Jun 15, 2004 |
| Priority date | — |
| Expiry date | Dec 27, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/02138
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A phase mask, for writing fiber Bragg gratings (FBG) in an optical fiber, adjusts the amplitude and the phase of the FBG, while maintaining a constant mean index of refraction of the fiber in a single pass. Specifically, the phase mask embodies the amplitude information so that the amplitude information is an integral part of the phase mask and preferably cannot be separated from the phase information. A first embodiment employs a reflective or opaque surface, defining a window, on the substrate of a phase mask controlling the amplitude of light passing through the phase mask. Another embodiment employs a polygonal shaped grating region on a clear substrate. A third embodiment interleaves regions of grating and smooth substrate surface. Preferred embodiments employ two areas of gratings with the areas disposed: perpendicularly, out of bandwidth or out of phase, relative to each other or additive.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.