Single-step interferometric radius-of-curvature measurements utilizing short-coherence sources
US9857169B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 20, 2016 |
| Grant date | Jan 2, 2018 |
| Priority date | — |
| Expiry date | Dec 20, 2036 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B2290/70
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An interferometer includes a short-coherence source and an internal path-matching assembly contained within its housing. Because path matching occurs within the housing of the interferometer, it is removed from external environmental factors that affect measurements. Therefore, a single cateye measurement of an exemplary surface can be performed in advance and stored as a calibration for subsequent radius-of-curvature measurements. In one embodiment, a path-matching stage is incorporated into a dynamic interferometer where orthogonally polarized test and reference beams are fed to a dynamic imaging system. In another embodiment, orthogonal linearly polarized test and reference beams are injected into a remote dynamic interferometer by means of one single-mode polarization-maintaining optical fiber.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.