Interferometer devices for determining initial position of a stage or the like
US9194694B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jan 30, 2013 |
| Grant date | Nov 24, 2015 |
| Priority date | — |
| Expiry date | Sep 5, 2033 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B9/02018
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An exemplary device has a stationary portion and a movable portion. The stationary portion has a first corner-cube, an optical system including a beamsplitter, and a light detector. The movable portion comprises a second corner-cube mountable on an object that is displaceable in a principal direction relative to the stationary portion. The beamsplitter splits a beam of collimated broadband light into a reference beam and a measurement beam that are directed by the optical system to make multiple roundtrip passes from the optical system to the respective corner cubes and back. The reference beam and measurement beam interfere with each other to produce a coherence envelope sensed by the detector, wherein a detected displacement of the coherence envelope corresponds to a respective position of the object in the principal direction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.