The diffraction of light

Abstract Diffraction as evidence of the wave nature of light-fundamental experimental facts. Grimaldi’s experiment. The Huygens principle. The Huygens-Fresnel principle. Fresnel’s diffraction integral. Fresnel zones. Graphical construction of diffraction patterns. Edge diffraction. The diffraction length of an optical beam. Near- and far-field zones of diffraction. The diffraction divergence of a beam in the far-field zone. The focusing of light as a diffraction phenomenon. Kirchhoff’s diffraction theory.