Scanning interferometry
US7102761B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 27, 2004 |
| Grant date | Sep 5, 2006 |
| Priority date | — |
| Expiry date | Apr 13, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/0675
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An interferometry method includes: imaging test light reflected from at least a first portion of a test surface to interfere with reference light on a camera and form an interference pattern, wherein the imaging defines a depth of focus for the light reflected from the test surface, and wherein the test light and reference light are derived from a common source; varying an optical path length difference between the test light and reference light over a range larger than the depth of focus, wherein the optical path length difference corresponds to a difference between a first optical path between the common source and the camera for the test light and a second optical path between the common source and the camera for the reference light; and maintaining the first portion of the test surface within the depth of focus as the optical path length difference is varied.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.