Differential plane mirror interferometer
US4752133A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 19, 1985 |
| Grant date | Jun 21, 1988 |
| Priority date | — |
| Expiry date | Dec 19, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B2290/70
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A differential plane mirror interferometer comprises a source (10) which emits a light beam containing two orthogonally polarized components of different frequencies; a source of a stabilized electrical reference signal (11) of a frequency corresponding to a difference frequency between the two components of the light beam; a tilted parallel plate (16) having regions of reflection, antireflection and polarization coatings for converting the input beam into two separated, parallel, orthogonally polarized beams; a half-wave retardation plate (29A, 29) located in one of the separated beams for converting the two separated, parallel, orthogonally polarized beams into two separated parallel beams with the same polarization; means including a polarizing beamsplitter (44), for causing each of the separated parallel beams with the same polarization to be reflected twice by one of two plane mirrors (71,70) to produce two parallel output beams with the same polarization; a half-wave retardation plate (29B, 29) located in one of the separated parallel output beams, with the tilted parallel plate (16) for converting the two separated parallel orthogonally polarized output beams having regions …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.