Near-null compensator and figure metrology apparatus for measuring aspheric surfaces by subaperture stitching and measuring method thereof
US9115977B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 20, 2012 |
| Grant date | Aug 25, 2015 |
| Priority date | — |
| Expiry date | Oct 12, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01M11/0271
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A variable near-null compensator for measuring aspheric surfaces by subaperture stitching includes a pair of counter-rotating CGH phase plates, each of the phase plates having a phase function including two terms Z5 and Z7 of Zernike polynomials. The phase plates are mounted on a pair of precision rotary center-through tables, wherein rotational axes of the pair of precision rotary center-through tables coincide with the optical axes of the phase plates. A figure metrology apparatus includes a wavefront interferometer, the test mirror mount, the near-null compensator and the mechanical adjustment components therefor. The optical axis of the near-null compensator coincides with the optical axis of the interferometer. A method for measuring aspheric surfaces by subaperture stitching includes the steps of mounting the test mirror, measuring the subapertures with the figure metrology apparatus, and finally processing the data by stitching.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.