Wavelength sensitive beam combiner with aberration correction
US6043935A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 17, 1998 |
| Grant date | Mar 28, 2000 |
| Priority date | — |
| Expiry date | Jul 17, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/0006
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A wavelength sensitive hologram which combines the 780 nm laser beam and the 650 nm laser beam to produce a compact DVD optical pickup. The 780 nm laser beam is incident on the hologram at an angle so that the first order diffraction from the hologram propagates along the optical axis of the hologram. The wavefront recorded on the hologram also contains aberration correction components so that the focused 780 nm laser beam on the CD substrate is nearly perfect or at least diffraction limited. The 650 nm laser beam is incident normal to the hologram plane so that the 0 order diffraction of the 650 nm laser beam remains propagating along the optical axis of the hologram.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.