Fraunhofer Diffraction -- from Eric Weisstein's World of Physics

Optics "> Diffraction v

Fraunhofer Diffraction

Fraunhofer diffraction is the type of diffraction that occurs in the limit of small Fresnel number . In Fraunhofer diffraction, the diffraction pattern is independent of the distance to the screen, depending only on the angles to the screen from the aperture. Let the distance coordinates in the aperture plane be and the distance coordinates in the projection plane (x, y). Writing the aperture factor as , the Fresnel-Kirchhoff diffraction integral gives the wavefunction at the projection plane as

where C is a constant, k is the wavenumber, R is the distance from the aperture to the projection plane, and the integral is taken over the aperture. For , (1) can be approximated by the two-dimensional Fourier transform Eric Weisstein's World of Math

where

are the angular coordinates.

Diffraction, Double Slit Interference, Fraunhofer Diffraction--Circular Aperture, Fraunhofer Diffraction--Double Slit, Fraunhofer Diffraction--Elliptical Aperture, Fraunhofer Diffraction--Rectangular Aperture, Fraunhofer Diffraction--Single Slit, Fresnel Diffraction, Fresnel Number, Fresnel-Kirchhoff Diffraction Integral, Poisson Spot