Device for measuring physical quantity using pulsed laser interferometry
US6168310A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 17, 1998 |
| Grant date | Jan 2, 2001 |
| Priority date | — |
| Expiry date | Mar 17, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L22/12
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Pulsed laser beams are applied to an object to be measured. A first laser beam of a pulsed laser beam having a first wavelength which is oscillated immediately after the rise of the pulsed laser beam, and a second laser beam having a second wavelength which is oscillated thereafter are used. Based on a difference between an intensity of first interfered light of reflected light of the first laser beam or transmitted light thereof, and an intensity of reflected light of the second laser beam or transmitted light thereof, temperatures of the object to be measured, and whether the temperatures are on increase or on decrease are judged. The method and device can be realized by simple structures and can measure a direction of changes of the physical quantities.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.