Single-layer reflective super broadband circular polarizer and method of fabrication therefor
US5691789A · kind A · utility
Inventors
Key dates
| Filing date | Oct 30, 1995 |
| Grant date | Nov 25, 1997 |
| Priority date | — |
| Expiry date | Oct 30, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E10/40
- WIPO fieldMicro-structural and nano-technology
- WIPO sectorChemistry
Abstract
The present invention relates generally to broadband, reflective circular polarizers and, more particularly, to single layer super broadband, reflective circular polarizers. The polarizers of the present invention are made from a film of material, like a polymer having a cholesteric order, in which a second liquid crystal material, like a nematic liquid crystal, is distributed in a non-linear fashion across the thickness of the film in a plurality of liquid crystal-rich and liquid crystal-depleted sites in the polymer. The resulting polarizers have band passes approaching 2000 nm and reflect circularly polarized light which is either left-handed or right-handed depending on the final spiral structure of the materials utilized. The material of the present invention is fabricated by mixing commercially available polymers having a cholesteric order, a second liquid crystal material and a photoinitiator at a temperature which maintains the mixture in a liquid state. The polymer and the liquid crystal are present in a ratio by weight of 1:2, for example, and the photoinitiator is present in an amount of 0.6% by weight, for example, in the mixture. The heated mixture is then subjected to…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.