场变换方法电磁波调控器件研究

Electro-magnetic (EM) wave manipulation technology is always the hot topic in EM wave propagation research, which is also the fundamental technology in realizing EM devices of EM wave probing，communication and signal processing. The traditional manipulation solutions are mainly based on natural materials with limitations in the functionality. Transformation Optic (TO) offer us the capability of manipulating the propagation direction of EM waves based on the extraordinary EM properties of the metamaterials. And the Field Transformation (FT) has been proposed as a complementary part to TO, which gains the ability of manipulating the wave impendence and polarization signature of an object based on the design of the transformation matrix. Such FT approach offers a new solution to manipulate EM wave and greatly broadens the domain of EM wave manipulation. And some EM devices based on FT approach have gain better performance than those based on traditional TO theories. Our project starts from investigating the intrinsic connections between the factors of the transformation matrix and the propagation characters of EM waves, to explore a new approach of EM wave manipulation. And we investigate the application capability of the FT devices through polarization manipulation, far-field radiation pattern manipulation, meta-surface design and the generation of OAM waves. We also investigate the realization method of the EM manipulation prototypes based on 3D printing technology. We will further develop the design approach of the EM wave manipulation devices based on metamaterial, which lay the root for EM manipulation devices with better performance.

电磁波调控技术始终是电磁波传播领域的研究热点，也是实现各种电磁波探测、通信、信息处理器件的关键技术。传统调控手段依赖天然材料，功能有局限性。光学变换方法利用人工电磁材料的奇异特性，可以对电磁波传播方向进行任意调控。而场变换方法是变换光学方法的延伸与扩展，通过对传播媒质的波阻抗及电磁耦合系数的设计，可实现对电磁波的幅度与极化进行调控，拓展电磁波调控的内涵；一些通过场变换方法设计的调控器件也已展现出更优越的性能。本项目通过分析与揭示场变换方法中变换矩阵设计与电磁波传播特征调控的本质联系，探索电磁波调控的新机制；基于人工电磁材料，从电磁波极化调制、远场辐射调控、超表面设计、螺旋波的实现等方面开展场变换方法电磁波调控器件的应用研究；结合3D打印技术，探索电磁波调控原型器件的实现方法。本项目的研究将进一步拓展人工电磁材料电磁波调控器件的设计方法，为高效、性能优异的电磁波调控器件及应用打下基础。

本项目基于本人在电磁超材料可调控电磁器件和超表面以及光学变换与场变换方法方面的研究基础，开展了场变换方法的电磁波调控机理研究，基于电磁超材料，并结合3D打印技术，从电磁波极化调制、远场辐射调控、超表面设计、实现螺旋波等方面开展了电磁波调控器件的设计与实现研究。项目进行四年以来，完成了以下研究内容：一、完善了场变换方法进行电磁波调控的理论模型，建立了场变换器件的性能表征方法。二、基于超材料和场变换方法设计了超宽带的半波片与四分之一波片，并在微波段和毫米波段结合3D打印技术进行了实验验证。三、基于超材料和场变换方法设计了一系列多功能电磁波极化调制超表面。四、基于实现的半波片实现了圆极化波到螺旋波的耦合转化超表面，并基于场变换方法的设计平台设计了一系列旋转相位调制器件。五、基于超材料和场变换方法，设计了一系列宽带电磁波吸波结构，并进行了实验验证。相应的成果在OPTICS EXPRESS、Scientific Reports等杂志上发表标注本项目SCI论文20余篇，其中本人为第一和通讯作者论文8篇，第一标注论文6篇。申请专利五项，其中获授权专利l两项。经过四年来的不断探索，项目组基本完成了申请书中制定的研究目标，完成了研究内容，甚至拓展了研究的方向，在超材料可调控超表面、宽带吸波器、可调谐吸波器等方面制备了一系列的电磁波调控器件，基本解决了项目制定拟解决的关键科学问题，研究成果也达到了申请书制定的成果要求。本项目的开展为场变换方法用于电磁波调控器件的设计打造了一定的应用基础，也为电磁超材料器件的设计和应用拓展了新的方向，具有一定的实用意义。