Testing of recessed surfaces at grazing incidence
US5532821A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 16, 1995 |
| Grant date | Jul 2, 1996 |
| Priority date | — |
| Expiry date | Mar 16, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/306
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An interferometer (10) includes a prism extender (50) appended to a prism (32) for directing a beam of light (42) into a recess (44) of a test piece (34). A first portion (42a) of the beam (42) refracts from a reference surface (54) of the prism extender (50) to an angle (.alpha.) of grazing incidence on a bottom surface (46) of the recess (44), and a second portion (42b) of the beam (42) reflects from the reference surface (54). The two portions (42 aand 42b) of the beam (42) recombine at the reference surface (54) forming an interference pattern indicative of differences between the reference surface (54) and the bottom surface (46) of the recess (44).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.