Apparatus and method for high-speed phase shifting for interferometric measurement systems
US8848271B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 27, 2014 |
| Grant date | Sep 30, 2014 |
| Priority date | — |
| Expiry date | Feb 27, 2034 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2200/08
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Described are a method and apparatus for high-speed phase shifting of an optical beam. A transparent plate having regions of different optical thickness is illuminated by an optical beam along a path of incidence that extends through the regions. The transparent plate can be moved or the optical beam can be steered to generate the path of incidence. The optical beam exiting the transparent plate has an instantaneous phase value according to the region in which the optical beam is incident. Advantageously, the phase values are repeatable and stable regardless of the location of incidence of the optical beam within the respective regions, and phase changes at high modulation rates are possible. The method and apparatus can be used to modulate a phase difference of a pair of coherent optical beams such as in an interferometric fringe projection system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.