Characterization of focusing performance of spiral zone plates with fractal structure

Zang Hua-Ping¹, Zheng Cheng-Long¹, Ji Zi-Wen¹, Fan Quan-Ping², Wei Lai², Li Yong-Jie³, Mu Kai-Jun¹, Chen Shu¹, Wang Chuan-Ke², Zhu Xiao-Li⁴, Xie Chang-Qing⁴, Cao Lei-Feng^{2, †}, Liang Er-Jun^{1, ‡}

(a) Intensity distribution of the main and subsidiary dark cores of FSZP, (b) detailed characteristics of main focus, (c) intensity profiles along x axis on main and subsidiary focal planes.