Evaluation of surface and subsurface characteristics of a sample
US4632561A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 30, 1985 |
| Grant date | Dec 30, 1986 |
| Priority date | — |
| Expiry date | Apr 30, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/8461
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus is disclosed for evaluating surface and subsurface features in a sample by detecting scattering of a probe beam. More particularly, the subject invention relates to the detection of thermal and/or plasma waves through the phenomenon of optical scattering. The apparatus includes a periodic excitation source for supplying energy to the surface of the sample to generate thermal and/or plasma waves. A radiation probe is directed to the surface of the sample within the area that is being periodically excited and in a manner that the probe beam is scattered from the excited area. Variations of the intensity of the scattered probe beam are detected and processed to evaluate surface and subsurface characteristics of the sample.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.