We propose axial line-focused spiral zone plates （ALFSZPs） for generating tightly focused X-ray vortex beams with ultra-long depth of focus （DOF） along the propagation direction. In this typical design, compared w...We propose axial line-focused spiral zone plates （ALFSZPs） for generating tightly focused X-ray vortex beams with ultra-long depth of focus （DOF） along the propagation direction. In this typical design, compared with the conventional spiral zone plates （SZPs） under the same numerical aperture （NA）, the DOF of ALFSZPs has been extended to an ultra-length by optimizing the corresponding parameters. Besides, it also exhibits lower side lobes and smaller dark cores in the whole focus volume. The diameters of dark cores increase as the topological charge value increases.展开更多
基金supported by the National Natural Science Foundation of China(Nos.11404290,61307019,11504333,and 61505178)the National Key Scientific Instruments and Equipments Development of Special Item,China(No.2012YQ130125)+1 种基金the Postdoctoral Science Foundation of Henan Province(No.2013008)the Program for Science&Technology Innovation Talents in Universities of Henan Province(No.172102210481)
文摘We propose axial line-focused spiral zone plates （ALFSZPs） for generating tightly focused X-ray vortex beams with ultra-long depth of focus （DOF） along the propagation direction. In this typical design, compared with the conventional spiral zone plates （SZPs） under the same numerical aperture （NA）, the DOF of ALFSZPs has been extended to an ultra-length by optimizing the corresponding parameters. Besides, it also exhibits lower side lobes and smaller dark cores in the whole focus volume. The diameters of dark cores increase as the topological charge value increases.
