Associated dual interferometric measurement method for determining a physical property of an object
US5596409A · kind A · utility
47Cited by
28References
19Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 22, 1995 |
| Grant date | Jan 21, 1997 |
| Priority date | — |
| Expiry date | Mar 22, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/8438
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention relates to an apparatus and method for measuring physical properties of an object, such as thickness, group index of refraction, and distance to a surface. The apparatus includes a non-coherent light interferometer (53) and a coherent light interferometer (55) in association so as to share a variable optical path delay element (54). Thickness measurements can be made, for example, of solids, liquids, liquids moving along a horizontal plane, or liquids flowing down a plane. Thickness measurements of multiple layers can be made.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.