Dispersion may be caused either by refraction or by diffraction.
The diffraction spectrum is therefore termed a normal spectrum.
This inflection of the light receives the name of Diffraction.
The halo diminishes in brightness from the centre outwards, and is probably due to the diffraction of light.
In 1818 he read a memoir on diffraction for which in the ensuing year he received the prize of the Acadmie des Sciences at Paris.
He took the spectrum produced by diffraction instead of refraction, and measured that.
Another way of obtaining considerable dispersion is by using a diffraction grating instead of a prism.
The diffraction phenomena of the atmosphere are produced by the water drops of clouds and fog, or sometimes by fine dust.
Diffraction, a term applied to the bending that rays of light undergo in passing close to the edge of an opaque body.
But the image of a star formed by a telescope is not a point but a minute disc, surrounded by a series of diffraction rings.