Difference between revisions of "Diffraction"
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Diffraction
</dt>
The process by which the direction of radiation is
changed so that it spreads into the geometric shadow region of an opaque or
refractive object that lies in a radiation field.
</dd>
Diffraction is an optical edge effect.
Reference to Huygens'
principle is a common means of explaining diffraction. Analysis of the
interference between individual Huygens wavelets which originate in the
vicinity of the edge of an irradiated body reveals that detectable amounts of
radiant energy must invade the nominal shadow zone of the object, and there,
by interference, set up characteristic energy distributions known as
diffraction patterns. The amount of diffractive bending experienced by
a ray is a function of wavelength; thus dispersion
occurs, although dispersion is in the opposite sense to that produced by
refraction.
</dd>
References
This article is based on NASA's Dictionary of Technical Terms for Aerospace Use
