Dual-frequency grating interferometer displacement measurement system
US9885556B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 28, 2013 |
| Grant date | Feb 6, 2018 |
| Priority date | — |
| Expiry date | Jul 10, 2034 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/38
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A dual-frequency grating interferometer displacement measurement system, comprises a dual-frequency laser, an interferometer, a measurement grating and an electronic signal processing component. The measurement system realizes displacement measurement based on grating diffraction, optical Doppler effect and optical beat frequency theory. Dual-frequency laser light is emitted from the dual-frequency laser and split into reference light and measurement light via a polarization spectroscope. The measurement light is incident to the measurement grating to generate positive and negative first-order diffraction. The diffraction light and the reference light form a beat frequency signal containing displacement information about two directions at a photo-detection unit, and linear displacement output is realized after signal processing. The measurement system can realize sub-nanometer and even higher resolution and accuracy, and is able to measure long horizontal displacement and vertical displacement at the same time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.