Fringe visibility enhancement arrangement and method
US4904082A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 27, 1988 |
| Grant date | Feb 27, 1990 |
| Priority date | — |
| Expiry date | Dec 27, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J9/02
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An arrangement for smoothing a coherent laser beam of a limited yet substantial coherence length due to the presence of several discrete optical frequencies therein is operative for subdividing the coherent laser beam into a plurality of partial beams of substantially the same intensity. Each of the partial beams is then conducted in a different path, the length of at least one of which differs from that of another path by a distance amounting to a fraction of the coherence length. At least some of the partial beams are subsequently combined into a coherent output beam in which the partial beam issued from the one path is shifted by the distance relative to that issued from the other path.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.