Optical recording medium, holographic recording and/or retrieval method and holographic recording and/or retrieval apparatus
US6909684B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 11, 2001 |
| Grant date | Jun 21, 2005 |
| Priority date | — |
| Expiry date | Jul 21, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/25
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A holographic recording and/or retrieval method and apparatus are provided. An optical recording medium is used which has a recording layer, formed on a surface of a transparent substrate, through which light having an incident angle of a predetermined value or more with respect to the surface is guided, and which changes a refractive index or absorption coefficient upon simultaneous irradiation of signal light of a predetermined wavelength and reference light, and can record holograms by holding the changed refractive index or absorption coefficient. During recording, a hologram is recorded by simultaneously irradiating the recording layer with signal light of predetermined wavelength and reference light. During retrieval, reading light of wavelength that does not change a refractive index or absorption coefficient of the recording layer is guided through the recording layer, and a hologram is retrieved by diffracted light produced when the reading light is guided through the recording layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.