Fabrication and applications of long-lifetime, holographic gratings in photorefractive materials
US5796096A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 13, 1995 |
| Grant date | Aug 18, 1998 |
| Priority date | — |
| Expiry date | Apr 13, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03H2001/0439
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Substantial improvements in photorefractive device lifetimes are provided by control of electron migration which results in the decay of gratings in photorefractive materials due to diffusion and other effects. A new class of photorefractive devices using compensating electronic and ionic gratings having relatively low efficiency but nonetheless usable gratings is provided by arranging the gratings to be reflective in a wavelength band outside the photo-excitation band of the photorefractive material, as by using an infrared operating wavelength. Longer lifetimes in high efficiency gratings are achieved by constant or periodic illumination of photorefractive materials to assure uniform charged distribution of electrons and maintenance of the ionic backbone grating.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.