Grazing incidence interferometer and method
US6249351A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 3, 1999 |
| Grant date | Jun 19, 2001 |
| Priority date | — |
| Expiry date | Jun 3, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B2290/30
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A two-beam interferometer illuminates a sample surface with light at grazing incidence angles for the purpose of analyzing a surface characteristic such as surface topography. The interferometer includes a diffractive-optic beam splitter, which separates an incoming light beam into measurement and reference beams and a diffractive-optic beam combiner, which produces an output beam by interfering portions of the reference beam with reflected portions of the measurement beam. Those portions of the reference wavefront and the measurement wavefront that interfere originate from substantially the same portion of the initial illumination wavefront.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.