Apparatus for making a high quality reflection type holographic optical element
US6236476A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 10, 1998 |
| Grant date | May 22, 2001 |
| Priority date | — |
| Expiry date | Apr 10, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03H1/20
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An apparatus for making a high quality reflection type holographic optical element (HOE) using a single input laser beam, including a reflective mirror, a holographic photoplate having a photo emulsion layer on a surface nearest the reflective mirror, a cassette for retaining the reflective mirror and the holographic photoplate, and a refractive index matching fluid containing a light absorbent dye for absorbing an input laser beam. The cassette is immersed in the fluid so that fluid is retained between the photo emulsion layer of the holographic photoplate and a reflective surface of the reflective mirror. Parasitic interference patterns are suppressed by heating the refractive index matching fluid with the input laser beam, which causes a shift of the phase of the parasitic beams with respect to the phase of the beams responsible for recording the HOE. If the photo emulsion layer of the holographic photoplate consists of a dichromated gelatin (DCG), then a photo sensitizer agent (e.g., ammonium dichromate; DCA) of the DCG is used as a light absorbent dye to be added in the refractive index matching fluid such that the photo sensitizer agent does not drain out of the DCG into the …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.