High contrast flatness interferometer
US4406543A · kind A · utility
2Cited by
1References
6Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 17, 1981 |
| Grant date | Sep 27, 1983 |
| Priority date | — |
| Expiry date | Jul 17, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/306
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Disclosed is an interferometer having an optical flat having a coated reference surface of aluminum whose thickness is in the range of 100-500 A (preferably about 300 A) covered with a coating of silicon dioxide of a thickness in the range of 1,000-10,000 A (preferably about 3,000 A). Such a coating on an optical flat when in engagement with a surface of an object to be tested greatly enhances the contrast of the interference fringes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.