Zhou Yan, Ji Rong, Teng Jinghua, Hong Minghui
Opt Lett. 2020 Feb 15;45(4):852-855. doi: 10.1364/OL.382872.
In this Letter, a novel, to the best of our knowledge, structural configuration on a transparent microsphere is proposed to engineer the focusing light field. By patterning a hybrid diffractive Fresnel zone plate structure on a partially milled microsphere using a focused ion beam, wavelength-dependent switching between mono-focal and multi-focal functionalities can be achieved. Generation of on-axis tri-foci and mono-focus light fields under high numerical-aperture (${\rm NA}\gt {0.67}$NA>0.67) conditions at two working wavelengths (405 nm and 808 nm) have been demonstrated both numerically and experimentally.
在本信函中，据我们所知，提出了一种用于透明微球的新型结构配置，以设计聚焦光场。通过使用聚焦离子束在部分研磨的微球上制作混合衍射菲涅耳波带片结构，可以实现单焦点和多焦点功能之间的波长依赖性切换。在两个工作波长（405纳米和808纳米）下，在高数值孔径（${\rm NA}\gt {0.67}$）条件下，通过数值模拟和实验均已证明了同轴三焦点和单焦点光场的产生。
