摘要
基于Fano共振超表面所具有的高品质因数Q以及电场局域特性设计了一种全介质超表面结构,探究了超表面结构参数与品质因数Q、调制深度之间的关系。通过改变结构实现了单重Fano共振至双重Fano共振的有效调控。对比同等参数下矩形柱与椭圆柱超表面结构的灵敏度,选择矩形柱结构并确定其最优参数。矩形柱超表面结构的品质因数Q最大可达3408,双重Fano共振峰的调制深度接近99%。通过仿真计算可知该结构对甲烷体积分数的测量灵敏度可以达到1.57 nm/%(对应dip1)和1.66 nm/%(对应dip2),对背景折射率的测量灵敏度为419.45 nm/RIU和395.7 nm/RIU,FOM(figure of merit)值分别为524.3 RIU-1和542.8 RIU-1。此外,入射光偏振角度对此传感结构的Fano共振透射光谱强度具有一定影响,这一特性为光学非对称传输、偏振角检测以及超表面多功能复用等提供了新思路。
Objective Nanostructures based on metallic materials can modulate the amplitude,phase,and polarization of electromagnetic waves owing to their surface plasmon resonance(SPR)properties.The interference between bright and dark modes forms Fano resonances in metamaterials.Excitation of the dark mode can effectively suppress far-field radiation and enhance near-field radiation.However,the significant heat loss of metallic materials limits their application in optics;therefore,only a few superconfigurable materials based on surface plasma excitations can be used in practical applications.Recent studies have shown that highly refractive index all-dielectric nanostructures with low absorption properties do not undergo heat loss,thus facilitating the realization of highperformance compact devices.In this study,we designed a fully dielectric nanopillar supersurface with a high Fano resonance quality factor,Q,and modulation depth.We hope our design can provide innovative ideas for asymmetric transmission,polarization angle detection,and super-surface multifunctional multiplexing.Methods In this study,the Fano resonance theory was simulated around a fully dielectric supersurface material.Maxwell s equations describe the electromagnetic-wave propagation law in space,and the equations can be solved to determine the response of the supersurface to the incident light.However,the analytical solution of Maxwell s equations cannot be obtained in general;therefore,the simulation results are typically obtained by solving a system of equations using numerical methods.The two widely used solution methods are the finite element method(FEM)and the finite difference in the time-domain method(FDTD).We used the FDTD Solutions software to simulate the supersurface and perform high-precision simulations to replace the more expensive prototype experiments.The periodic boundary conditions were set in the x-and y-directions owing to the periodicity of the superlattice structure,and a perfect matching layer(PML)was set in the z-direction.In addi
作者
刘海
任紫燕
陈聪
高鹏
乔昱嘉
冯越
罗灏
Liu Hai;Ren Ziyan;Chen Cong;Gao Peng;Qiao Yujia;Feng Yue;Luo Hao(The Engineering Research Center of Intelligent Control for Underground Space,Ministry of Education,China University of Mining and Technology,Xuzhou 221116,Jiangsu,China;School of Information and Control Engineering,China University of Mining and Technology,Xuzhou 221116,Jiangsu,China)
出处
《中国激光》
EI
CAS
CSCD
北大核心
2023年第10期176-185,共10页
Chinese Journal of Lasers
基金
国家自然科学基金(51874301)
徐州市重点研发项目(KC20162)。
