High accuracy linear displacement interferometer with probe
US5133599A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 2, 1991 |
| Grant date | Jul 28, 1992 |
| Priority date | — |
| Expiry date | Jan 2, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B2290/70
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A high accuracy linear displacement interferometer capable of measuring changes in displacement of two plane mirror surfaces (60, 61) comprises a source (10) of an input beam (12) with two linear orthogonally polarized components which may or may not be of the same optical frequency, a birefringent optical element (40) and a quarter-wave phase retardation plate (42) for converting the input beam (12) into two separated, parallel, oppositely handed circularly polarized beams (16, 17); a first plane mirror (60) comprising one of the two (60, 61) plane mirror surfaces; a second plane mirror (61) nominally parallel to and rigidly connected to the first plane mirror (60) surface comprising the other of the two plane mirror surfaces; the birefringent optical element (40), the quarter-wave phase retardation plate (42), a right angle prism (48) with reflective, orthogonal faces, and a pair of retroreflectors (44, 45) causing each of the separated, parallel, oppositely handed circularly polarized output beams (32, 33); the quarter-wave phase retardation plate (42) and the birefringent optical element (44) converting the two separated, parallel, oppositely handed circularly polarized output …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.