Fractal diffractive lenses with improved diffraction efficiency
In this paper we review the focusing and imaging
properties of fractal photon sieves and DevilĀ“s lenses
designed in order to improve the diffraction efficiency of
fractal diffractive lenses. It is shown that these lenses
provide a smoothing effect on the higher order foci of a
conventional fractal zone plate. Furthermore, the
characteristic self-similar axialesponse of the fractal
zone plates is always preserved. This behavior predicts
an improved performance of fractal lenses as image
forming devices with an extended depth of field and a
reduced chromatic aberration.