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

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Fraunhofer Diffraction--Rectangular Aperture

For an extended rectangular aperture of width and height , Fraunhofer diffraction gives the wavefunction

where C is a constant, k is the wavenumber, and and are angles from the source, so the intensity is given by

Fraunhofer Diffraction, Fraunhofer Diffraction--Single Slit