Precompensation of polarization errors in heterodyne interferometry
US7365857B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 21, 2005 |
| Grant date | Apr 29, 2008 |
| Priority date | — |
| Expiry date | Nov 14, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B2290/70
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Apparatus and methods for adjusting the polarizations of the components of an input beam to reduce leakage caused by imperfections in an interferometer are disclosed. The apparatus includes an interferometer positioned to receive an input beam that includes two components having different frequencies and different polarizations, the interferometer including a polarizing beam splitter positioned to spatially separate the input beam into two intermediate beams, the first intermediate beam corresponding to the first component and the second intermediate beam corresponding to the second component, where imperfections in the interferometer cause leakage of one of the components into the intermediate beam corresponding to the other of the components. The apparatus further includes a polarization compensator that includes at least one retardation plate positioned to adjust the polarizations of the components of the input beam to reduce the leakage caused by the imperfections in the interferometer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.