Magneto-optical head employing optical fiber connected stationary and movable portions
US5245491A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jun 1, 1990 |
| Grant date | Sep 14, 1993 |
| Priority date | — |
| Expiry date | Jun 1, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B11/10543
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical fiber type magneto-optical head is capable of realizing satisfactory reductions in size and weight of a movable portion of an optical head. An extinction-type form of the optical fiber type magneto-optical head comprises a first optical device for condensing a polarized light beam and leading the light beam into a polarization-maintaining optical fiber, a second optical device for focusing light emerging from the optical fiber into a beam spot on a magnetic recording medium, a detector for detecting via the optical fiber light reflected from the magnetic recording medium with a change in polarized state, and an azimuth rotator disposed between the second optical device and the optical fiber, wherein the azimuth rotator is designed so that the angle of optical rotation upon one pass therethrough is EQU .theta.k/2.+-.n.multidot.45.degree. where PA0 .theta.k/2.+-. : the Kerr rotation angle of a magnetic recording film of the recording medium, PA0 N= 0, 1, 2, . . . . A differential-type form of the optical fiber type magneto-optical head comprises, instead of the above-mentioned azimuth rotator, an azimuth rotator so designed that the angle of optical rotation upon one pass …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.