基于复合光栅和梯度超表面的多功能器件设计  

Multifunctional Device Design Based on Composite Gratings and Gradient Supersurfaces

作　　者：刘海[1,2] 赵思怡 陈聪 高鹏[1,2] 戴耀威 赵佳明[1,2] 万寅辉 路祥宇 王馨艳 李雷 LIU Hai;ZHAO Siyi;CHEN Cong;GAO Peng;DAI Yaowei;ZHAO Jiaming;WAN Yinhui;LU Xiangyu;WANG Xinyan;LI Lei(The Engineering Research Center of Intelligent Control for Underground Space,Ministry of Education,China University of Mining and Technology,Xuzhou 221116,China;School of Information and Control Engineering,China University of Mining and Technology,Xuzhou 221116,China)

机构地区：[1]中国矿业大学教育部地下空间智能控制工程研究中心,徐州221116 [2]中国矿业大学信息与控制工程学院,徐州221116

出　　处：《光子学报》2023年第9期55-65,共11页Acta Photonica Sinica

基　　金：国家重点研发计划(No.2021YFC2902704);国家自然科学基金(No.51874301)。

摘　　要：设计了一种金属/介质/金属复合光栅与梯度超表面相结合的多功能器件。通过复合光栅的非对称结构实现光的非对称传输,当调制后的波矢量与表面等离极化激元的波矢量相匹配时,金属光栅激发的表面等离极化激元产生单波段光传输;通过梯度超表面实现光的异常反射。当x偏振态光波入射时,不同入射方向可在不同波段激发表面等离极化激元,由于上下光栅的不同周期和非对称的介质环境,光栅可分别在1128 nm和1550 nm处实现高透射率;另外在反向入射方向,该器件在1300~1400 nm整个波段表现为零吸收,反射率大于90%,可作为反射器。当y偏振态光波入射时,在反向入射方向器件通过相位梯度超表面实现异常反射。该结构可为各种偏振相关的多功能器件和集成光学元件提供参考。Most of the current research can only realize the asymmetric transmission of light singly,in the face of the demand for multifunctional application scenarios,the design of multifunctional integrated devices has become a development trend.Therefore,the combination of grating and super-surface,which can realize different functions in different incidence and polarization states,is a multifunctional device combining a metal/medium/metal composite grating and a gradient super-surface structure.The asymmetric transmission of light is realized through the asymmetric structure of the composite grating,and when the modulated wave vector matches the wave vector of the Surface Plasmon Polaritons(SPPs),the SPPs excited by the metal grating produce single-band light transmission,and the anomalous reflection of light is realized through the gradient hypersurface.When an x-polarized light wave is incident,the SPPs are unidirectionally excited at 1550 nm in the forward-incidence direction,and the forward transmittance at this wavelength is up to 0.9.In the reverse-incidence direction,the SPPs are unidirectionally excited at 1128 nm,and the backward transmittance at this wavelength is up to 0.86.Due to the different periods of the upper and lower gratings and the difference in permittivity at the incident interfaces,the surface-iso-polarized excitations can be excited in a single-band light transmission.The upper and lower gratings cannot excite SPPs in the same band at different incidence directions,and the reverse transmission is suppressed in the forward excitation band and vice versa.In order to obtain the best performance of the asymmetric transmission characteristics,the parameters of the device are optimized to enhance the interaction between the beam and the grating.The effect of the grating transverse position on the transmission spectrum is investigated.Changes in the grating transverse position alter the strength of the coupling effect,leading to the splitting of the transmission peaks,the emergence of double peaks or

关 键 词：复合光栅 非对称传输 梯度超表面 表面等离极化激元 异常反射 

分 类 号：O436[机械工程—光学工程]