Angular displacement measuring interferometer
US5028137A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 13, 1989 |
| Grant date | Jul 2, 1991 |
| Priority date | — |
| Expiry date | Feb 13, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B2290/70
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An angular displacement interferometer system capable of measuring accurately changes in angular displacement comprises a source (10) of a frequency stabilized input beam with two linear orthogonally polarized components; a tilted parallel plate or shear place (16) with regions of reflection, antireflection, and polarizing coatings for converting the input beam (12) into two separated, parallel, orthogonally polarized beams (30, 31); a half-wave retardation plate (29) located in one of the separated beams (31) for converting the two separated, parallel, orthogonally polarized beams (30, 31); into first and second beams which are spatially separated parallel, and have the same polarization (30, 33); a polarizing beamsplitter (40) and quarter-wave retardation plate (44) for transmitting the first and second beams (34, 35) to a fixed plano mirror (70) nominally perpendicular to the first and second beams for reflecting the first and second beams back into the quarter-wave retardation plate (44), polarizing beamsplitter (40), and retroreflector (48) for producing third and fourth beams (56, 67); a rotatable angle prism (72, 93) attached to the mechanical apparatus whose angular displac…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.