Laser interferometer for measuring object displacement over large distances
US5638177A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 15, 1995 |
| Grant date | Jun 10, 1997 |
| Priority date | — |
| Expiry date | Feb 15, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B2290/70
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A laser interferometer, used for measuring displacement over long distances (e.g. 100 meters) includes an integral laser/detector unit 10, which emits a beam 12 of laser light. The fraction of the beam 12B which passes undiverted through a beam splitter 14 is laterally displaced by a periscope 18, which is positioned close to the laser 10. After passage through the periscope 18, the undiverted beam is incident upon a large retroreflector 20, whose size is such that the beam reflected by retroreflector 20 is laterally displaced by an amount greater than the lateral displacement due to passage of the beam through the periscope 18. Opaque housing 26 of the periscope 18 is used to screen reflected light from entrance into the laser cavity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.