Holographic element
US5164847A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 20, 1991 |
| Grant date | Nov 17, 1992 |
| Priority date | — |
| Expiry date | Jun 20, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B5/32
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A transmission holographic element (30) comprises a holographic material (330) deposited onto a substrate (31) to form a composite substrate structure. The substrate (31) is coated with a mirror coating (32) prior to the deposit of the holographic material (33) which is reflecting at the reading wavelength and non-reflecting at the recording wavelength. This allows the use of substrates that need not be of good optical quality because when the holographic element is exposed to light at the reading wavelength, light is reflected by the mirror coating before passing through the substrate. In addition, the mirror coating is protectred from damage during processing since it is between the substrate (31) and holographic material (33).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.