Fresnel diffraction by one-dimensional regular fractals

This is the authors' abstract. We don't add key points for this paper.

Some properties of the Fresnel diffraction field produced by a Cantor bars aperture are investigated by numerical evaluations of the Fresnel integral. It is found that intensity distributions on the optical axis have a periodicity which includes symmetry, when plotted against a 2 /( lambda z) where a is the length of an object, lambda is the illumination wavelength and z is the distance of an observation point from the object. The period depends on the level of Cantor bars and shows a ninefold increase as the level of the object increases by one. Furthermore, as the level of Cantor bars increases, intensity distributions on the optical axis become invariant gradually from the far- to the near-field region.