Abstract
Needle beams are widely used in advanced applications due to their high intensity, high resolution, and extended depth of focus. In this work, the generation of needle beams through transmitting azimuthally polarized beams to polarization-insensitive metasurfaces is presented. Defocus phase profiles and annular apertures were adopted to obtain needle beams, respectively. A relatively long depth of focus (${16.9}\lambda$) with subdiffraction beam size (${0.41}\lambda$) was obtained. The introduction of metasurfaces can significantly simplify an optical system compared with traditional methods utilizing complex optical elements. This study may contribute to photolithography, microscopy, particle manipulation, and acceleration.
© 2021 Optical Society of America
Full Article | PDF ArticleMore Like This
Weichao Yan, Zhongquan Nie, Xueru Zhang, Yuxiao Wang, and Yinglin Song
Appl. Opt. 56(7) 1940-1946 (2017)
Zhongsheng Man, Changjun Min, Luping Du, Yuquan Zhang, Siwei Zhu, and Xiaocong Yuan
Opt. Express 24(2) 874-882 (2016)
Mehdi Veysi, Caner Guclu, Ozdal Boyraz, and Filippo Capolino
J. Opt. Soc. Am. B 34(2) 374-382 (2017)