Direct slope measurement shearing interferometer
US4660978A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 19, 1984 |
| Grant date | Apr 28, 1987 |
| Priority date | — |
| Expiry date | Dec 19, 2004 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J9/0215
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An improved method and apparatus for measuring the aberrated wave slope of an optical beam. The apparatus includes a shearing interferometer having a reference mirror 14 and a steerable mirror 16 mounted perpendicularly to one another with a beam splitter 10 disposed at a 45.degree. angle to each. The beam splitter 10 directs a portion of the incident beam to the reference mirror to form a reference beam 20 and transmits a portion 22 of the incident beam to the steerable mirror. The steerable mirror 16 is pivoted about two mutually perpendicular axes to form a shearing interference pattern at a detector array 24 when a portion of the incident beam is reflected off the steerable mirror 16 and combines with the reference beam 20 reflected off the reference mirror. The reference mirror 14 is periodically displaced to modulate the reference beam 20. In operation, the steerable mirror 16 is first oriented pivotally about a first axis perpendicular to the propagation axis of the incident beam to a pre-selected angle and the reference mirror is then periodically displaced. The variations in detector intensities are sampled and stored N times during this reference mirror displacement. The …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.