Beam shuttering interferometer and method
US5231468A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 6, 1991 |
| Grant date | Jul 27, 1993 |
| Priority date | — |
| Expiry date | Nov 6, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J2009/0249
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus resulting in the simplification of phase shifting interferometry by eliminating the requirement to know the phase shift between interferograms or to keep the phase shift between interferograms constant. The present invention provides a simple, inexpensive means to shutter each independent beam of the interferometer in order to facilitate the data acquisition requirements for optical interferometry and phase shifting interferometry. By eliminating the requirement to know the phase shift between interferograms or to keep the phase shift constant, a simple, economical means and apparatus for performing the technique of phase shifting interferometry is provide which, by thermally expanding a fiber optical cable changes the optical path distance of one incident beam relative to another.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.