Method and apparatus for employing a light source and heterodyne interferometer for obtaining information representing the microstructure of a medium at various depths therein
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United States of America Patent
Stats
-
Sep 10, 1996
Grant Date -
N/A
app pub date -
Jun 14, 1994
filing date -
Jun 15, 1993
priority date (Note) -
In Force
status (Latency Note)
Importance
Abstract
A low coherence light beam is split into first and second light beams, and the frequency of the first light beam is shifted. The first and second light beams are then combined with each other at a position at which the optical path difference between the two light beams is larger than the coherence length of the low coherence light beam. The combined light beam is guided to a position in the vicinity of a medium having light scattering properties and split into a third light beam, which travels reversely to the direction of travel of the combined light beam, and a fourth light beam, which is irradiated to the medium. A light beam scattered backwardly from a predetermined depth in the medium is caused to interfere with the third light beam, and the intensity of the resulting interference light beam is detected. Optical heterodyne detection of the intensity of the backward scattered light beam is carried out in accordance with the detected intensity of the interference light beam, and information representing the microstructure of the predetermined deed portion in the medium is thereby obtained.
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- 170 Citation Count
- G01B Class
- 98.81 % this patent is cited more than
- 29 Age