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-Feng2, †, Liang Er-Jun1, ‡
       

Diffraction patterns of the main and subsidiary foci for FSZP with different TCs.