基于石墨烯编码超构材料的太赫兹波束动态调控研究

Development of dynamic control beam with wide bandwidth and multifunction has become a key issue in the field terahertz (THz) technology. Although, the programmable metamaterial for microwave provide a approach to multifunction control terahertz beam, it is still greatly limited to modulating efficiency and bandwidth due to large loss and difficult fabrication of tunable devices such as varactor diodes in THz frequency. Thus, as a result of the tunability of carrier mobility and conductivity at THz frequencies, graphene is chosen to be incorporated into coding metamaterials in our project, in which the characteristic control of THz beams will be studied. The main contents are listed as following: (1) The new control mechanism of THz beam based on graphene coding metamateials, which includes constructing mathmatical model of dynamic modulation process, and revealing the dependence of modulated THz wave beams on voltage. (2) We will design hybrid graphene coding metal metamaterial, which can be desired to realize multi-modulation to the frequency, amplitude and phase of THz beams. (3) Proposal for structured graphene of coding metamaterial. We will design the periodic coding sequences of 010101……with different voltage for different column bit element and dynamic control the coding sequence, which can be expected to realize spatial parameters modulation to the beam steering, beam switching, beam width, and so on. The application of our research will supply the technical support for the development of novel THz modulator devices with excellent performance.

如何实现宽带、多功能动态调控波束一直是太赫兹(THz)领域亟待解决的难点问题。微波波段可编程超构材料为多功能调控THz波束提供了研究思路，但是变容二极管等可控器件在THz波段存在损耗增大、加工不易等缺点，使其对THz波调控效率及带宽等方面均受到较大限制。而石墨烯电导率动态可调性覆盖了大部分THz波段，因此本项目将结合石墨烯和编码超构材料优点,研究THz波束调控特性,其具体内容包括:(1)研究石墨烯编码超构材料调控波束新机理，建立动态调控数理模型，揭示电压与波束变化关系;(2)设计石墨烯薄膜与金属编码超构材料杂化结构，实现波束频率、幅度、相位等多参数调控;(3)提出石墨烯结构化的编码超构材料，利用不同电压调控不同列的bit单元构造诸如010101……等周期性编码并对序列动态调控,实现波束扫描、转换、波束宽度等空间参数调控。该项目的实施将为研发性能优异的THz调控器件提供技术支持。

如何实现宽带、多功能动态调控波束一直是太赫兹(THz)领域亟待解决的难点问题。本项目根据研究方案，有机结合石墨烯和超构材料的新颖电磁特性优势，深入开展基于石墨烯的超构材料太赫兹调控波束机理和特性研究，取得了一系列的研究成果：1)提出了一种石墨烯带的太赫兹1bit编码超构材料，通过不同编码序列实现太赫兹波束的数目、频率、幅度等参数多功能动态，为灵活调控太赫兹波提供了一种新的途径；2)研究了一种金属-石墨烯复合的新型超构材料滤波器，通过改变石墨烯的费米能级，实现太赫兹频段的动态可调控滤波效果，建立了DoseResp和Quartic两种动态调控理论模型，为太赫兹调控提供了理论支持；3)提出了一种金属-石墨烯层复合的新型超构材料调制器，能够实现高性传输系数和频率的动态调制，将在宽带通信等方面具有重要的应用前景；4)探索了一种石墨烯-金属复合结构的编码超构材料，能够实现宽频带内远场太赫兹波束的聚焦和波束数目调控，为宽带太赫兹调制器提供了一种途径；5)研究了一种基于透射型编码超构材料，通过编码序列不同实现对太赫兹波束数目、波束形状、波束频率的调控，为调控太赫兹波提供了一种简单途径；6)研制了一种全介质的低损耗超宽带透射型编码超材料，解决了金属结构损耗大等问题，实现了对太赫兹波束数目、相位等参数低损耗调控；7)提出了一种基于石墨烯连接的拓扑网络超材料，解决了超构材料调控电磁波带宽窄等问题，实现对太赫兹宽带完美调控；8)研制了一种微流控集成超构材料，流体耗尽层的阻尼效应与超表面的共振响应平行式耦合实现了对THz波透射强度和相位差调制。本项目的研究为研发性能优异的THz调控器件提供技术支持，将在宽带通信、生物医学检测等方面具有重要的应用价值。在本基金项目的资助下，项目研究进展顺利并超额完成了预期目标，已在Carbon, ACS Applied Electronic Materials, Photonics Research, Optics Express等期刊上发表SCI、EI收录论文18篇，获得国家发明专利2项。