Monolithic quadrature detector
US7315381B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 26, 2004 |
| Grant date | Jan 1, 2008 |
| Priority date | — |
| Expiry date | Aug 8, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B2290/70
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A compact monolithic quadrature detector generates four signals from an input beam including orthogonally polarized object and reference beam components provided by an interferometer. The single input beam may be split into four output beams using a first beam splitting interface between two prisms, reflections at two air interface surfaces of the prisms, and a second beam splitting element. Different respective predetermined phase shifts may be imposed on the respective output beams by coatings on the beam splitting surfaces, which impart a different phase shift to the components of a transmitted beam as compared to a reflected beam. The four relatively phase shifted output beams may be directed through polarizers onto respective detectors to provide four signals usable to eliminate many common mode errors and determine the phase difference between the components of the original input beam with high accuracy.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.