Broadband diffractive diffuser and associated methods
US6118559A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 5, 1998 |
| Grant date | Sep 12, 2000 |
| Priority date | — |
| Expiry date | May 5, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S359/90
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A broadband diffractive diffuser contains at least three levels, with approximately a phase shift of .pi. between at least two of the at least three levels. Such a diffuser provides light with more than two phasor vectors at the zero order. The presence of the more than two phasor vectors reduces the zero order diffraction efficiency at non-design wavelength, increasing the usefulness of the diffuser at wavelengths other than the design wavelength. Preferably, the diffractive diffuser includes a plurality of regions, approximately 50% of an area of the plurality of regions presenting a phase shift of .pi. at a design wavelength, approximately 25% of the area of the plurality of regions presenting a phase shift of 2.pi. at the design wavelength, and approximately 25% of the area of the plurality of regions presenting a phase shift of 0 at the design wavelength. Such a diffractive diffuser may be formed by logical operations between two diffractive diffuser patterns, by adding two diffractive diffuser patterns, or by pixel-by-pixel scanning.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.