人工周期性电磁材料的物理特性及其潜在应用研究

Recently, artificial periodic electromagnetic (EM) materials have attracted much interest due to their novel physical properties. Most of the attentions has focused on two kinds of artifical EM materials, metamaterials and photonic crystals, because they can precisely control the transmission of EM waves. This project will discuss the relation of some physical properties of the two artificial materials. We will investigate and compare the properties of the phase shift of the metamaterials and dielectric photonic crystals, and will try to establish their equivalent mechanism based on their properties of phase shifts, and then we may find an efficient way to realize low-loss metamaterials by dielectric photonic crystals. We will also investigate the properties of the phase shift of photonic crystals composed of metamaterials. When the metamaterials are introduced to the photonic structures, the influence to the properties of transmission phase shift and reflection phase shift of the photonic crystals will be discussed. We will try to present the physical mechanism of the appearence of tunneling modes inside the photonic band gap from the phase shift point of view. We will also investigate the exciting conditions and transmission properteis of the surface plasmon polariton (SPP) in the photonic crystals containing metamaterials. The coupling effect among the SPP waves along different interfaces will be analyzed. Combining the photonic band structures of the photonic crystals, we will try to realize the selected excitation of electric- and magnetic- SPPs and analyze the controllability of the transmission properties of the SPPs. The research of this project can not only find more potential applications of photonic crystals and metamaterials, but also provide a new way for designing micoelectronic devices.

近年来, 人工周期性电磁材料的新颖物理性质已获得了广泛的关注，其中超材料（metamaterial）和光子晶体这两种人工电磁材料，以其对电磁波传输的精确控制能力，引起了人们极大的兴趣。本申请将分析两者在某些物理特性上的内在联系及潜在应用价值。我们将研究并对比超材料与介电质光子晶体的相移特征，建立两者在相移上的相互等效关系，得到由介电质光子晶体等效低损耗超材料的高效途径。进一步研究由超材料构造的光子晶体的相移特性，探讨超材料的引入对光子晶体的透射、反射相移性质的影响，从相移角度上探讨光子带隙内的隧穿透射模的形成机制。还将研究含超材料光子晶体中表面等离激元（SPP）的激发条件和传输特性，探讨各界面SPP之间的相互耦合作用，结合光子晶体的能带结构，实现对电性和磁性SPP的选择性激发和传输控制。通过本申请项目的研究，可望拓展光子晶体和超材料的应用前景，为微光电子器件的研制和开发提供新的方向。

人工电磁微结构能实现天然材料所不具备的“超常”电磁波操控能力，在超分辨率成像、传感器件、太阳能电池、亚波长光学波导等领域具有广泛的应用前景。本项目针对光子晶体、超材料等亚波长电磁微结构的物理特性及其潜在应用展开研究，主要完成了三个方面的工作：（1）掌握了介电质光子晶体与超材料两种电磁微结构的反射相移规律与关联，建立了两者在传输相移特征上的等效机制，给出了在光子晶体异质结、超材料异质结中界面态产生的谐振条件，通过实验测量证实了理论的预测。（2）研究了含周期性微结构的表面等离激元波导中的等离激元模式劈裂、Fano共振、光场耦合与局域、负折射、非线形效应等现象，由此设计了一系列全光器件，如基于表面等离激元的多通道滤波器、对比度超过41dB的全光二极管、单向吸收开关、可调谐折射率传感器等。（3）研究了波在含石墨烯、半导体的薄膜结构中的传输规律，提出了在石墨烯层上覆盖介质薄膜层，可有效消除基底效应导致的石墨烯调制器性能的振荡，由此设计了相对工作带宽达55%且调制深度稳定为76%的宽带太赫兹调制器。进一步利用掺杂半导体的损耗所导致的非平凡反射相移，设计了宽带太赫兹吸收器。项目的研究成果先后在多个学术期刊上发表，其中在Small、Scientific Reports、Optics Letters、Optics Express等SCI收录的国际核心期刊上发表学术论文11篇。通过本项目的研究，更加深入地理解了人工电磁微结构对波的传输特性影响的物理机制，并由此设计出了一系列新型光电子器件，对人工微结构领域的研究和应用拓展提供了新的思路。