摘要
高Q值共振超表面以其对局域电磁场的显著增强而在纳米光子学中受到广泛关注。基于全介质材料独特的电磁属性,提出了一种方形晶格对称性破缺的全介质纳米孔阵列超表面,通过打破方形晶格原胞的面内对称性来激发近红外区域的高Q值Fano共振。在垂直入射平面波的激发下,该超表面实现了极化独立的双重简并模态Fano共振以及极化依赖的三重非简并模态Fano共振,后者具有更高的Q值与更强的电磁局域性能。采用数值模拟探究了晶格扰动参数对三重非简并模态Fano共振特性的影响。结果表明,三重非简并模态Fano共振的Q值与局域电场强度受晶格扰动参数控制,通过优化晶格扰动参数,三重非简并模态Fano共振的Q值可同时高达1.8×10^(4),2.7×10^(4),1.9×10^(4),其局域电场强度可同时高达2×10^(4),3×10^(4),1.5×10^(4)。
Resonant metasurfaces with a high Q factor have received widespread attention in nanophotonics due to their significant enhancement effect in local electromagnetic fields.On the basis of the unique electromagnetic properties of alldielectric materials,an all-dielectric nanohole array metasurface with a symmetry-broken square lattice is proposed in this paper.The in-plane symmetry of the square lattice unit cell is broken to excite multiple Fano resonances with a high Q factor in the near-infrared region.Under the excitation of plane waves at a normal incidence,the proposed metasurface can realize the double degenerate Fano resonance independent of polarization and the triple nondegenerate Fano resonance dependent on polarization,and the latter has a higher Q factor and stronger electromagnetic locality.The numerical simulation is performed to investigate the influence of lattice-perturbed parameters on the properties of the triple nondegenerate Fano resonance.The results reveal that the Q factor and the local electric field intensity of the triple nondegenerate Fano resonance are controlled by lattice-perturbed parameters.Through the optimization of latticeperturbed parameters,the Q factor of the triple nondegenerate Fano resonance can be simultaneously up to 1.8×10^(4),2.7×10^(4),and 1.9×10^(4),and their local electric field intensity can be simultaneously up to 2×10^(4),3×10^(4),and 1.5×10^(4).
作者
陈颖
李美洁
王建坤
赵蒙
Chen Ying;Li Meijie;Wang Jiankun;Zhao Meng(Hebei Province Key Laboratory of Test/Measurement Technology and Instrument,School of Electrical Engineering,Yanshan University,Qinhuangdao 066004,Hebei,China)
出处
《光学学报》
EI
CAS
CSCD
北大核心
2022年第15期178-185,共8页
Acta Optica Sinica
基金
国家自然科学基金(61201112)
河北省重点研发计划项目(19273901D,20373301D)
河北省自然科学基金(F2020203066)
中国博士后基金项目(2018M630279)
河北省博士后择优资助项目(D2018003028)
河北省高等学校科学技术研究项目(ZD2018243)。
关键词
表面光学
光学超表面
多重Fano共振
方形晶格
高Q值
电磁局域增强
optics at surfaces
optical metasurface
multiple Fano resonances
square lattice
high Q factor
electromagnetic local enhancement
