The photorefractive effect
Abstract
The photorefractive effect, a process in which light alters the refractive index of a material by altering the arrangement of atoms in a crystal and causing the material to act as a prism or lens to deflect light, is examined. It is noted that beam fanning, or stimulated, forward photorefractive scattering, and other photorefractive effects have been exploited in such applications as coherent beam excisors, optical interconnection elements, phase-conjugate mirrors, novelty filters, and edge enhancement of images. Beam fanning also plays an important role in phase conjugate mirrors made from photorefractive materials which cause reflected light to be time reversed, thereby offering many applications in the fields of optical communications, high-power lasers, and optical computing. The novelty filter is another example of the application that takes advantage of the energy-exchange mechanism by highlighting whatever is changing in a highly complex scene.
- Publication:
-
Scientific American
- Pub Date:
- October 1990
- DOI:
- 10.1038/scientificamerican1090-62
- Bibcode:
- 1990SciAm.263d..62P
- Keywords:
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- Crystal Lattices;
- Laser Beams;
- Optical Computers;
- Refractivity;
- Electric Fields;
- Optical Properties;
- Phase Conjugation;
- Refracted Waves;
- Optics