Fresnel and Fraunhofer name the near and far-field versions of this phenomenon, which is also described in terms of wavefronts by Huygens principle.
One principle important to understanding this phenomenon is used by radio engineers to find the ratio between metal and slot impedances. Electrons passing through a nickel crystal undergo this effect, as discovered by Davisson and Germer. Babinet showed the equivalence of two versions of this phenomenon, and one version of it is described by a formula with a constant of 1.22. Fresnel and Fraunhofer name the near and far-field versions of this phenomenon, which is also described in terms of wavefronts by Huygens principle. It produces an Airy disk when occurring in a small hole. This behavior also occurs in a double-slit setup. For 10 points, name this phenomenon in which light bends as it passes through an opening or around an object.
One principle important to understanding this phenomenon is used by radio engineers to find the ratio between metal and slot impedances.
Diffraction