Overview of the fabrication procedures. (a) Schematic illustration of GS-EBL for the Au-TKZP lens with diameter of 100 µm and outermost zone width of 250 nm. (b) SEM micrographs at a tilt of 45° for the replicated TKZP profiles in PMMA as a template for Au electroplating. (c) The fabricated TKZP lens in Au. (d) The fabricated FZP lens with a beamstop after gold electroplating. A 2 µm-wide trench crossing the center of the plate was deliberately arranged in testing samples to inspect the trapezoid kinofom profiles. White lines are the digitized curves (Au-TKZP+) of the actual zone profiles of Au-TKZP.