Two-color hologram recording/reproducing apparatus
US6373806B1 · kind B1 · utility
Assignees
Inventors
Key dates
| Filing date | Aug 2, 2000 |
| Grant date | Apr 16, 2002 |
| Priority date | — |
| Expiry date | Aug 2, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03H2001/0268
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A two-color hologram recording/reproducing apparatus is capable of directing interferable signal light and reference light into a hologram recording medium to record an information signal carried by the signal light. The hologram recording medium is sensitive to a first light at a first wavelength in an ultraviolet or short-wavelength visible light band to develop light induced absorption. The apparatus includes a light source for irradiating the hologram recording medium with the first light, a laser light source for irradiating the hologram recording medium with signal light and reference light at a second wavelength longer than the first wavelength after the first light is irradiated, and a gate light source for directing gate light at a third wavelength into the hologram recording medium. The gate light causes the hologram recording medium to develop a recording sensitivity to activate or inactivate a refractive index grating in accordance with existence or non-existence of a light interference pattern formed by the signal light and the reference light.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.