Patent · US Expired

Heterodyne receptor system and arrangement for visualizing optical transmission images

US5249072A · kind A · utility

2Cited by
14References
12Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 24, 1991
Grant dateSep 28, 1993
Priority date
Expiry dateMay 24, 2011

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01N2021/1787
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

The present invention provides a receptor system in which laser light from a laser source is directed onto a sample, the transmitted light from which is photomixed by a half mirror with laser light different in frequency from laser light from a local oscillator source, and the photomixed light is received by a receptor element dividing a light propagating zone into a plurality of sub-zones, said receptor element having an exit end, at which a spatial zone, which is defined between different points and in which interference occurs, is limited within a spatially resolvable minimum unit, to form a Fraunhofer diffraction image, whereby the 0 order diffraction image of the Fraunhofer diffraction image is partly or wholly detected by a photodetector, or alternatively a diffraction image at most n times as large as the 0 order spectrum is detected by the photodetector. By extracting a beat component from the photomixed light in this manner, a transmission image can be separated from scattered components for detection. With light including too many scattered components such as that transmitted through the human body or the like, it is possible to obtain information relating to an absorber.…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.