Reference lens for interferometer and interferometer that uses it
US6798585B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jan 21, 2003 |
| Grant date | Sep 28, 2004 |
| Priority date | — |
| Expiry date | May 3, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B13/00
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A reference lens for an interferometer is constructed so that light transmitted by a partially reflecting reference spherical surface may be converged, toward a focal point that coincides with the center of curvature of the reference spherical surface, and reflected from a subject spherical surface that also has its center of curvature at the focal point. Measurement of the shape of the subject spherical surface is possible based on the interference of two light beams, one reflected by the subject spherical surface and one reflected by the reference spherical surface. The reference lens, which may include five or six lens components or lens elements, includes a negative meniscus lens component, a positive lens group, and a positive lens component. Specified conditions are satisfied to provide a reference lens that has favorable correction of aberrations, is compact, and can measure the surface accuracy of a wide range of convex spherical surfaces.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.