Apparatus and methods for reading multilayer storage media using short coherence length sources
US5748598A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 22, 1995 |
| Grant date | May 5, 1998 |
| Priority date | — |
| Expiry date | Dec 22, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S5/141
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Apparatus and methods for reading multilayer optical data storage media are described. The apparatus includes a short coherence length light source and an optical system. The optical system focuses the light from the source onto the layers of the storage media. The coherence length of the source is less than 100 microns or less than the spacing between the layers. The Rayleigh range within the storage media may also be less than the spacing between the layers. The apparatus may include a detector for measuring alterations in light reflected from each layer of the storage media caused by data. The source may be any short coherence length source including superluminescent diodes, mode locked lasers, multi-longitudinal mode laser diode, or rare earth doped amplified spontaneous emission sources.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.