Single beam AC interferometer
US4968144A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 9, 1989 |
| Grant date | Nov 6, 1990 |
| Priority date | — |
| Expiry date | Mar 9, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/0427
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A single beam interferometer (10) comprises an intensity modulated laser beam (16) having a focus area for heating a test area (18) on the surface of a sample (12) producing a thermal bump (20). An unfocused probe laser beam (30) is directed toward the solid at an angle and has a beam area greater than the focus area of the heating beam (16). The sample (12) has a reflective surface for reflecting the probe beam (30). The reflected beam (31) comprises an AC beam portion (32) refracted by the thermal bump (20) and a DC beam portion (34) reflected off the unheated surface of the sample (12). The interference pattern (36) produced by the reflected beam (31) is detected and processed to obtain optical, elastic and thermal parameters of the sample (12).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.