Grating writing method and apparatus
US6434300B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 31, 2000 |
| Grant date | Aug 13, 2002 |
| Priority date | — |
| Expiry date | Aug 31, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/02152
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The invention provides a method of forming a grating structure on a photosensitive waveguide, involving: moving the waveguide relative to a light source in the longitudinal direction of the grating, directing coherent light from the light source perpendicularly to the direction of relative movement of the waveguide and irradiating spaced-apart regions of the waveguide to form the grating structure, modulating the light and, as a separate step, passing the light through a shutter in its passage between the light source and the waveguide, and controlling the shutter to effect shuttering of the light in synchronisation with the relative movement of the waveguide during formation of the grating structure, in order to control the irradiation of said waveguide so as to keep constant the refractive index in the waveguide core averaged over a full period of said grating structure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.