基于超表面波带片的远场偏振全息加密  

Far-Field Polarized Holographic Encryption by Metasurface Zone Plates

作　　者：夏天 谢振威 袁小聪 Xia Tian;Xie Zhenwei;Yuan Xiaocong(Nanophotonics Research Centre,Institute of Microscale Optoelectronics&State Key Laboratory of Radio Frequency Heterogeneous Integration,Shenzhen University,Shenzhen 518060,Guangdong,China)

机构地区：[1]深圳大学纳米光子学研究中心,微纳光电子学研究院,异质异构集成全国重点实验室,广东深圳518060

出　　处：《中国激光》2023年第18期202-208,共7页Chinese Journal of Lasers

基　　金：广东省基础与应用基础研究重大项目(2020B0301030009);国家自然科学基金(61935013,61975133);深圳市科技计划基础研究重点项目(JCYJ20180507182035270,JCYJ20200109114018750);深圳市孔雀团队项目(KQTD20170330110444030)。

摘　　要：超表面是一种具有灵活的偏振操纵功能的新型材料。为了获得远场偏振全息图像,通常需要添加透镜等光学元件。笔者利用超表面波带片的灵活偏振操纵及聚焦功能实现了一种新颖的远场偏振全息加密技术。在该技术中,两个自旋复用的超表面波带片被集成到单个介质超表面器件中,其中超表面的振幅(右旋圆偏振转化率)用来编码奇数和偶数环形区域的波带片,而其相位调制则用来编码透射右旋圆偏振光和左旋圆偏振光的两个全息图。此外,二维码(QR码)和振幅型/相位型全息图用于进一步隐藏加密信息,以提高信息的安全性。所提加密技术有望进一步提升数据安全性和隐私保护水平,推动光学信息加密和高密度数据存储等领域的技术发展。Objective Metasurfaces have flexible polarization manipulation functions;however,a lens must be added to obtain the desired farfield-polarized holographic images.This study demonstrates a novel far-field polarization holographic encryption method using flexible polarization manipulation and the focusing capabilities of metasurface zone plates.Two spin-multiplexed metasurface zone plates are integrated into a single metasurface device,where the amplitude(right-handed circular polarization conversion rate)of the metasurface is used to encode the odd and even annular regions of the zone plates,and its phase modulation is utilized to encode two holograms of the transmitted right and left circularly polarized light.Additionally,QR codes and amplitude-only/phase-only holograms are used to hide encrypted information and improve data security.The proposed encryption technology is expected to enhance data security and privacy protection and promote the development of optical information encryption and high-density data storage.Methods The metasurface consisted of odd and even zones of a metasurface zone plate.When left-handed circularly polarized light is incident on the surface,the odd and even zones transform the light into right-and left-handed circularly polarized light,respectively.The polarization conversion efficiencies are 100%and 0%for the odd and even zones,respectively.For the odd zones,the amplitude of the transformed right-handed circularly polarized light is equal to one.For the even zones,the amplitude of the transformed lefthanded circularly polarized light is also one.Therefore,the amplitudes of the odd and even zones can be considered amplitude-only odd and even Fresnel zone plates,respectively.In addition,the phases of the odd and even zones were designed as holograms corresponding to right-and left-handed circularly polarized light,respectively(Fig.2).Thus,the two types of holograms have their respective holographic images in the same focal plane of the amplitude-only odd and even Fresnel zone plates.H

关 键 词：表面光学 超表面波带片 远场偏振全息加密 QR码 全息 

分 类 号：O436[机械工程—光学工程]