Abstract

Fractional and de-centered phase spiral zone plates (SZPs) are proposed for anisotropic edge enhancement using a femtosecond laser. The transmission functions of the two types of phase SZPs are deduced and the diffraction distributions are theoretically analyzed and simulated as well. By setting the fractional topological charge $p$ and the orientation angle $\vartheta$ of a fractional SZP (FSZP), the intensity and the direction of the anisotropic edge enhancement can be controlled. A de-centered SZP (DSZP) can be obtained by shifting the coordinates of the traditional phase SZP while the topological charge equals to 1. The intensity and direction of the anisotropic edge enhancement can be controlled by setting the displacement distance $r_0$ and the azimuthal angle ${\phi }_0$ of a DSZP. The anisotropic edge enhancement of the two phase SZPs was experimentally demonstrated with a phase pattern and living biological cells under femtosecond laser illumination.

© 2017 Optical Society of America

Fractional spiral zone plates

Lai Wei, Yulin Gao, Xianlun Wen, Zongqing Zhao, Leifeng Cao, and Yuqiu Gu
J. Opt. Soc. Am. A 30(2) 233-237 (2013)

Fractal spiral zone plates

Ziwen Ji, Huaping Zang, Chunzhen Fan, Junqiao Wang, Chenglong Zheng, Lai Wei, Chuanke Wang, and Leifeng Cao
J. Opt. Soc. Am. A 35(5) 726-731 (2018)

Spiral phase filtering and orientation-selective edge detection/enhancement

Guohai Situ, Giancarlo Pedrini, and Wolfgang Osten
J. Opt. Soc. Am. A 26(8) 1788-1797 (2009)

Isotropic and anisotropic edge enhancement with a superposed-spiral phase filter

Zhe Li, Shengmei Zhao, and Le Wang
Opt. Express 29(20) 32591-32602 (2021)

Image edge enhancement using Airy spiral phase filter

Yi Zhou, Shaotong Feng, Shouping Nie, Jun Ma, and Caojin Yuan
Opt. Express 24(22) 25258-25268 (2016)