Interferometric apparatus and sample characteristic determining apparatus using such apparatus
US9945655B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 12, 2013 |
| Grant date | Apr 17, 2018 |
| Priority date | — |
| Expiry date | Dec 23, 2033 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B2290/20
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An interferometer apparatus comprising: a short coherence length or broadband light source; a light director to direct light from the light source along a measurement path to a surface of a sample and also along a reference path to a reference surface; a wavelength disperser to cause wavelength dispersion of light along one of the measurement and the reference paths; a combiner to cause light from the sample surface and light from the reference surface to produce an interference pattern or interferogram; a detect—or to detect intensity values of the interference pattern as a function of wavelength; and a determiner to determine from the detected intensity values the wavelength at which the measurement and reference paths are balanced, wherein the wavelength disperser is at least one of: a grating wavelength disperser, a prism wavelength disperser, and an optical dispersive medium.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.