Length standard comparison method and apparatus utilizing holographic interferrometry
US4197010A · kind A · utility
1Cited by
3References
8Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 6, 1977 |
| Grant date | Apr 8, 1980 |
| Priority date | — |
| Expiry date | Oct 6, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B9/021
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A hologram of a wave front reflected by the end of a primary standard, either produced by exposure of a plate in the apparatus or synthesized by computer, is illuminated by a laser with a direct beam and with a beam reflected from the end of a standard to be measured mounted in a reference position. Interference fringes are produced on a screen and the standard to be measured is moved from a reference position to a position in which the reflected wave front coincides with the wave front recorded by the hologram while the fringes are counted to determine the difference in length.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.