Interferometric measurement method and interferometric measurement arrangement
US11879721B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 22, 2022 |
| Grant date | Jan 23, 2024 |
| Priority date | — |
| Expiry date | Apr 8, 2042 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B2290/30
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A measurement method for interferometrically measuring the shape of a surface (112) of a test object (114). A test wave (125-1, 125-2) directed at the test object has a wavefront that is at least partially adapted to the desired shape of the surface, and a reference wave (128-1, 128-2) directed at a reflective optical element (130-1, 130 2) has a propagation direction that deviates from the propagation direction of the test wave (125-1, 125-2) for each of two input waves by diffraction at a diffractive element (124). For each wavelength, the test wave is superimposed after interaction with the test object with the associated reference wave after the back-reflection at the first reflective optical element. The test and reference waves are diffracted again at the diffractive element for superposition. An interferogram produced by the superposition is captured in a capture plane (148-1, 148-2). The interferograms are jointly evaluated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.