基于柔性超材料的环偶极子太赫兹电磁响应特性及功能器件研究

As one of the basic research frontier in the field of electromagnetics, toroidal dipoles have been shown to be important in aerospace,broadband communication and astrophysics domains, which has already shown prospective application and scientific significance. Here, an in depth study of the THz toroidal dipole will be studied with theoretical analysis, numerical simulation, structure design and experimental verification via flexible metamaterial. Flexible metamaterial has characteristics such as transparency, deformation and robustness, which has broken the application limitation of traditional silicon-based metamaterials.The relation among the electric multipole,the magnetic multipole and the toroidal dipole will be explored, and the principle of toroidal dipole's generation will be investigated. The design of metamaterial unit structure is designed, and the equivalent circuit modle is obtained. The properties of toroidal dipole resonance are optimized according to the general principle of toroidal dipole design. On the basis of theoretical study, the virtues of toroidal dipole such as high Q value, sensitivity, tunable characteristic can be developed into functional devices, such as terahertz sensor, frequency modulator, using existing lithography processing and measured methods, which can enrich the family of terahertz functional devices. The theoretical methods and experimental techniques obtained from this research will reveal a path to design new generation toroidal dipole metamaterial and functional devices, which can be applied to other electromagnetic domain.

环偶极子现象是电磁学领域的前沿基础研究之一，在量子计算机、宽带通讯和天体物理等领域具有重大应用前景和科学意义。本项目拟采用理论分析、数值仿真、结构设计和实验验证相结合，通过柔性超材料研究环偶极子太赫兹波段下的电磁响应特性。柔性超材料具有变形性和鲁棒性等特点，打破传统太赫兹硅基超材料的应用局限；利用理论分析和数值仿真方法，建立“环偶极子-电多极子-磁多极子”作用规律及理论模型，获得环偶极子产生的物理机制；实现超材料的单元结构设计，获得等效电路模型，掌握环偶极子超材料设计一般性方法，优化环偶极子在太赫兹频段下电磁响应特性。以理论研究为基础，利用现有的光刻加工和表征手段，结合环偶极子谐振高Q值、敏感性、可调谐性等特点，研制太赫兹传感器、调频器等功能器件，丰富太赫兹功能器件家族。进一步验证太赫兹环偶极子理论，获得从设计、制备到实验表征的系列关键技术和新方法，为推广到其它电磁波段奠定扎实基础。

环偶极子现象是电磁学领域的前沿基础研究之一，在量子计算机、宽带通讯和天体物理等领域具有重大应用前景和科学意义。课题立足于环偶极子在太赫兹频段下的新规律和新机制及应用前景，主要从两方面研究，一是，利用柔性超材料深入研究环偶极子在太赫兹频段的物理机制；二是，利用环偶极子独特的电磁响应特性实现太赫兹功能器件的研发。在此研究过程中，进行了一些有意义研究工作：1、设计多种基于柔性介质基底（Polyimide和Mylar）的柔性环偶极子超材料，通过理论分析、数值仿真、结构设计优化环偶极子电磁响应特性，建立“环偶极子-电多极子-磁多极子”作用规律及理论模型，获得环偶极子产生的物理机制。2、以理论研究为基础，利用现有的光刻加工和表征手段，制备高品质因数太赫兹传感器、调频器等功能器件，丰富太赫兹功能器件家族。获得从设计、制备到实验表征的系列关键技术和新方法。3、研究MgO-ZnO-TiO2基陶瓷在太赫兹频段下电磁性能，研究表明通过掺杂Ca可改变MgO-ZnO-TiO2基陶瓷微观结构，进而改变折射率以及吸收系数等参数，该材料有望用于太赫兹环偶极子介质超材料设计。4、研究不同厚度压电薄膜聚偏二氟乙烯（PVDF）在太赫兹频段下电磁性能。PVDF薄膜的压电特性有可能用于太赫兹领域，该薄膜有望用于太赫兹可调谐环偶极子超材料中。