量子电子学报, 2019, 36 (5): 532, 网络出版: 2019-10-14
金属-介质-金属三棱柱结构 超表面中的磁电耦合
Magnetoelectric coupling in metal-dielectric-metal triangular prism structure metasurface
微纳光学 反射率差 极化率张量 超表面 共振 micro-nano optics reectance difference polarizability tensors metasurface resonance
摘要
基于亚波长纳米单元(超原子)的超表面结构革新并极大丰富了光场调控技术,从理论 上研究并设计具有独特性质和功能的超表面结构在光场调控研究中具有重要价值。利用极化率张量理论计算了对称和非对称 金属-介质-金属(MDM)正三棱柱超原子的诱导电响应、磁响应、磁电响应和电磁响应,设计出偏振无关的周期性MDM正三棱柱 超表面,分别通过时域有限差 分(FDTD)仿真模拟和理论计算的方法得到MDM超表面的透射谱和反射谱,两者能符合得很好。并发现对称超表面结构的反射谱 对入射光传播方向不敏感,而非对称超表面结构的反射谱在共振频率附近对入射光传播方向有依赖。研究结果对利用不对称超 原子设计具有任意反射系数的超表面具有指导作用。
Abstract
Metasurface structures based on subwavelength nanoscale units (meta-atoms) have been innovated and greatly enriched the technique of light field regulation. Therefore, it is of great value to study and design metasurface structures with unique properties and functions in light field regulation. The induced electric, magnetic, electro-magnetic and magneto-electric responses within the symmetrical and asymmetrical metal- dielectric- metal (MDM) triangular prism meta-atoms are calculated by using the polarizability tensors of the meta-atoms. The polarization-independent MDM triangular prism periodic structure is designed. The transmission and reflectance spectrum of the MDM meta-surfaces are studied by finite difference time domain (FDTD) simulation and theoretical calculation method. The two results are well consistent with each other. It is found that the reflection spectrum of the symmetric metasurface is identical whether the light incident is from upward or downward. However, the reflection spectrum of the asymmetric metasurface depends on the direction of the incident light when the incident light frequency is around the resonant mode. The results reported here are helpful for the realization of asymmetrical metasurface with arbitrary reflectivity.
倪赛健, 王晗, 王勇, 鲁拥华, 王沛. 金属-介质-金属三棱柱结构 超表面中的磁电耦合[J]. 量子电子学报, 2019, 36(5): 532. NISaijian, WANG Han, WANG Yong, LU Yonghua, WANG Pei. Magnetoelectric coupling in metal-dielectric-metal triangular prism structure metasurface[J]. Chinese Journal of Quantum Electronics, 2019, 36(5): 532.