Systems, devices, and methods for aperture-free hologram recording
US11409238B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 29, 2018 |
| Grant date | Aug 9, 2022 |
| Priority date | — |
| Expiry date | Dec 12, 2040 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03H2270/55
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The apertures typically used for hologram recording create unwanted secondary holograms by diffracting light. Aperture-free hologram recording eliminates these unwanted secondary holograms. Aperture-free hologram recording includes applying a mask to the holographic recording medium. The mask controls the size of the recorded hologram like an aperture but does not create unwanted secondary holograms. Hologram fringes are only present in the desired recording area and a thin boundary region. The mask may be present during recording, or the mask may be used to pre-bleach the holographic recording medium. Pre-bleaching the holographic recording medium renders a portion of the holographic recording medium insensitive to light, the hologram is recorded in the light-sensitive portions of the holographic recording medium.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.