Cartoon of the emergence of edge fringes 

This animation shows the emergence of edge fringes due to diffraction as a function of distance of the detector from an opaque screen with a knife edge. Its calculation involves the so-called `Fresnel integrals’, C(v) and S(v), and is equal to , whereby and . The red line follows the position of the first minimum, which approximately follows a square-root dependence with screen-detector distance.