Particle measurement utilizing orthogonally polarized components of a laser beam
US4636075A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 22, 1984 |
| Grant date | Jan 13, 1987 |
| Priority date | — |
| Expiry date | Aug 22, 2004 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/21
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Particle measurement is disclosed utilizing orthogonally polarized components of a laser beam. A laser beam is split into orthogonally polarized components and at least one of the components is thereafter beam shaped to have a modified dimension. The components are then recombined and focused to provide a beam combination that is directed through a particle containing volume where scattering of the components occurs by the particles. With the components superimposed upon one another, a localized volume is created with one beam being contracted to a smaller volume than the other beam with the illumination intensity ratios thereat being either greater or less than unity depending upon the optics selected. Particle scattering events are observed within the localized volume in order to define those particles transitting through its central uniform intensity region (sample volume) independent of viewing circumstance by comparing scattered intensity ratios of the orthogonally polarized beam components using a polarizing analyzer and a pair of detectors. The scattering intensities measured of those particles transitting through the preferred sample volume are retained as valid size measur…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.