Cyclic error compensation in interferometry systems
US7616322B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 3, 2006 |
| Grant date | Nov 10, 2009 |
| Priority date | — |
| Expiry date | Aug 1, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70775
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An interference signal S(t) is provided from interference between two beams directed along different paths. The signal S(t) is indicative of changes in an optical path difference n{tilde over (L)}(t) between the different paths, where n is an average refractive index along the different paths, {tilde over (L)}(t) is a total physical path difference between the different paths, and t is time. An error signal is provided to reduce errors in an estimate of {tilde over (L)}(t). The error signal is derived at least in part based on one or more collective properties of a distribution of multi-dimensional values. At least one of the multi-dimensional values in the distribution is generated from a plurality of samples of the signal S(t) (e.g., samples of the signal captured at different times).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.