Magneto-optic information storage system utilizing a self-coupled laser
US4571650A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 6, 1983 |
| Grant date | Feb 18, 1986 |
| Priority date | — |
| Expiry date | Sep 6, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B11/10532
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical information storage system wherein information is read from a magneto-optical storage medium by indicating the storage medium with a first laser beam generated by a semiconductor laser and exploiting the self-coupling effect of the semiconductor laser in response to light reflected from the storage medium to generate a second laser beam. A Faraday rotator is disposed in an optical path along which the reflected light from the magneto-optical storage medium returns to the semiconductor laser and a polarization rotating angle of the Faraday rotator is selected so that the oscillating polarization plane of the semiconductor laser is changeable in dependence upon the perpendicular magnetization direction of the magneto-optical storage medium. A linear polarizer is interposed between the semiconductor laser and a photodetector to extract from the second laser beam at least one polarization component parallel or perpendicular to a junction plane of the semiconductor laser with the extracted component being detected by the photodetector.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.