微机械平面重构太赫兹超常媒质的动态电磁特性及可控功能器件研究

In recent years, the limited tuning ranges and selections of tunable materials in tunalbe terahertz metamaterials severely restrict the developments and applications of tunable terahertz decvices based on metamaterials. In this project, a novel method is proposed that miromachined in-plane reconfiguration or translation of the metamaterial unit cells via electrostatic actuators are used to replace the nonlinear response of tranditional tunable materials or out of plane reconfiguration of MEMS structure. In this way, the terahertz metamaterials with large tuning range, real-time and dynamic tunability are presented, which is important to further research and application. We mainly investigate the micromachined in-plane reconfigurable terahertz metamaterials. Firstly, based on a method combined numerical simulation, theoretical analysis and experimental correction, as the unit cells are translated and reconfigured, the field distributions of micromachined in-plane reconfigurable terahertz metamaterial are studied to create the corresponding equivalent circuit model. Secondly, the dynamic electromagnetic properties of micromachined in-plane reconfigurable terahertz metamaterial are investigated when the unit cells are drived by the different voltages and speeds. Then, the optimized structures are fabricated, measured, improved and perfected. Finally, the controlled functional devices based on micromachined in-plane reconfigurable terahertz metamaterial are further explored. The expected research results of this project possibly provide flexible platform and new freedom degree for the design and fabrication of tunable terahertz metamaterials.

近年来，可调太赫兹超常媒质遇到调谐范围小和调谐材料可选性窄等瓶颈，严重制约太赫兹功能器件的发展和应用。本项目提出利用静电驱动微机械平面重构的结构单元平移或重构代替传统调谐中材料非线性响应或非平面MEMS结构运动，构造大范围、实时动态调谐的太赫兹超常媒质，对促进超常媒质更深层次应用具有重要意义。本项目以“微机械平面重构太赫兹超常媒质”为研究对象，采用数值仿真、理论分析和实验修正相结合方法，从结构单元重构出发，研究结构单元内部各元件间平移或重构时微机械平面重构太赫兹超常媒质的场分布规律，构建等效电路模型；研究不同电压和速度驱动下结构单元重构或平移时微机械平面重构太赫兹超常媒质的动态电磁特性，并对优化的结构进行试验加工、测试以及理论改进与完善；进而探索基于微机械平面重构太赫兹超常媒质在可控功能器件应用。本项目的预期研究成果有望为可调太赫兹超常媒质的设计和制备提供灵活易控的平台和新的自由度。

针对当前可调谐太赫兹超常媒质研究中遇到调谐材料可选择范围窄、批量制备难和调谐范围小等瓶颈，本项目突破传统可调太赫兹超常媒质的研究思维方式，从太赫兹超常媒质的结构单元（超常分子）出发，研究了微机械平面重构太赫兹超常媒质结构单元各元件之间重构时的电磁响应和可调谐电磁特性，并提出了基于微机械平面重构太赫兹超常媒质的电磁耦合模型和等效电路模型，建立了微机械平面重构太赫兹超常媒质的构造理论，揭示了微机械平面重构太赫兹超常媒质的调谐机理；在此基础上，提出了不同类型的微机械平面重构太赫兹超常媒质结构，并制备和开发出可动态调谐的调制器、滤波器、以及模式转换器等太赫兹功能器件。另外，项目也研究了基于石墨烯结构太赫兹超常媒质的调谐机理，并设计和开发出相应的太赫兹功能器件。因此，本项目的研究成果解决了现有可调太赫兹超常媒质调谐范围小、工艺复杂、功能单一和难以灵活控制等缺点，对可调谐太赫兹超常媒质的结构单元设计和灵活调控的功能器件开发具有重要的指导意义。