Figure 8
Calculated diffraction efficiency for the two stacked high-resolution ordinary gold FZPs with an outermost zone width of [\Delta r] = 20 nm and photon energy of 6.2 keV. (a) The diffraction efficiency decreases rapidly as a function of the separation distance ld when the two stacked FZPs have identical diameters. (b) The diffraction efficiency is kept constant when the diameter of the second FZP is optimized for every separation distance. (c) The diffractive efficiency for an experimentally realisable system in which the second FZP has a diameter adjusted for a separation distance of ld = 25 µm.  [article HTML]