Alignment of diffraction gratings
US4200395A · kind A · utility
135Cited by
5References
41Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 3, 1977 |
| Grant date | Apr 29, 1980 |
| Priority date | — |
| Expiry date | May 3, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/7049
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
First and second plates are formed with like periodic patterns. A laser beam illuminates the second plate through the alignment marks of the first plate to provide a pair of diffracted beams that are detected with alignment being indicated when the beams are of the same intensity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.