Compact Littrow encoder
US7864336B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 28, 2008 |
| Grant date | Jan 4, 2011 |
| Priority date | — |
| Expiry date | Jan 28, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70775
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A Littrow encoder is disclosed. The encoder includes first and second interferometers and a beam splitter assembly that splits a first instrument light beam into first and second interferometer input beams and directs these beams into the first and second interferometers, respectively. Each interferometer generates a measurement beam and a reference beam and directs the measurement beam toward a grating on a surface from which the measurement beam is diffracted, the measurement beam from the first interferometer striking the surface at a Littrow angle that is the negative of the angle at which the measurement beam from the second interferometers strikes that surface. Each interferometer includes at least one intensity detector that generates a signal related to an intensity of light in a combined light beam that includes the reference and measurement beams from that interferometer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.