Xu Ning, Hao Yuan, Jie Kaiqian, Qin Shuai, Huang Hui, Chen Li, Liu Hongzhan, Guo Jianping, Meng Hongyun, Wang Faqiang, Yang Xiangbo, Wei Zhongchao
Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices, School of Information and Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006, China.
Nanomaterials (Basel). 2021 Mar 14;11(3):729. doi: 10.3390/nano11030729.
The zoom metalens has been a research hotspot for metasurfaces in recent years. There are currently a variety of zoom methods, including dual metalenses, micro-electromechanical system metalenses, polydimethylsiloxane metalenses and Alvarez metalenses. However, for most metalenses, zooming is achieved by manipulating the relative displacement of two or more metasurfaces. Therefore, these methods seem inadequate when faced with more precise zooming requirements, and the precise control of the phase distribution cannot be achieved. In this paper, we innovatively propose an electrically-driven zoom metalens (EZM) of one-dimensional based on dynamically controlling barium titanate (BaTiO, BTO) antennas. Using the electro-optic effect of BTO crystals, we can apply a voltage to change the refractive index of BTO nanopillars ( = 2.4-3.6), thereby accurately controlling the phase distribution of column antennas. The proposed EZM can achieve 5× zoom ( = 10-50 μm), with advantages, such as high-speed optical amplitude modulation, ultra-compactness, flexibility and replicability. It can be applied in fields that require ultra-compact beam focusing, zoom imaging, and microscopic measuring.
近年来，变焦超构透镜一直是超表面领域的研究热点。目前存在多种变焦方法，包括双超构透镜、微机电系统超构透镜、聚二甲基硅氧烷超构透镜和阿尔瓦雷兹超构透镜。然而，对于大多数超构透镜而言，变焦是通过操控两个或更多超表面的相对位移来实现的。因此，当面对更精确的变焦要求时，这些方法似乎并不充分，无法实现对相位分布的精确控制。在本文中，我们创新性地提出了一种基于动态控制钛酸钡（BaTiO₃，BTO）天线的一维电驱动变焦超构透镜（EZM）。利用BTO晶体的电光效应，我们可以施加电压来改变BTO纳米柱的折射率（n = 2.4 - 3.6），从而精确控制柱状天线的相位分布。所提出的EZM能够实现5倍变焦（λ = 10 - 50 μm），具有高速光振幅调制、超紧凑、灵活和可复制等优点。它可应用于需要超紧凑光束聚焦、变焦成像和微观测量的领域。
