Laser-amplified motion detector and method
US5029023A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 29, 1989 |
| Grant date | Jul 2, 1991 |
| Priority date | — |
| Expiry date | Sep 29, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/004
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Method and apparatus for measuring nanometer or picometer surface displacements in a target surface. A laser beam is directed against the target surface, and time-dependent variations in laser output power are measured. These variations, which are due to non-specular reflection of the incident beam by the target and reentry of the retroreflected light into the laser cavity, are used to determine time-dependent displacements at the target surface, based on a linear relationship between the measured power variations and surface displacements. The invention is useful for determining microscopic surface features of a surface, for high-density laser optical disc data storage and retrieval, and as an ultrasensitive transducer for sound or mechanical vibrations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.