Measuring device for interferometric determination of a shape of an optical surface
US10527403B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jan 18, 2019 |
| Grant date | Jan 7, 2020 |
| Priority date | — |
| Expiry date | Jan 18, 2039 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B2290/50
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A measurement apparatus (10) for determining a shape of an optical surface. An illumination module (16) produces an illumination wave (34), an interferometer (18) splits the wave into a test wave (50), which is directed onto the optical surface, and a reference wave (52). The relative tilt between the waves produces a multi-fringe interference pattern (66) in a detection plane (62) of the interferometer when the waves are superposed. A pupil plane (28) of the illumination module is arranged in a Fourier plane of the detection plane and the illumination module is configured to produce the illumination wave so that the intensity distribution thereof in the pupil plane includes at least one spatially isolated and contiguous surface region (38) such that a rectangle (74) with the smallest possible area fitted to the surface region or the totality of surface regions has an aspect ratio of at least 1.5:1.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.