Developing anisotropic media for transformation optics by using dielectric photonic crystals

非技术描述：变换光学(TO)是基于坐标变换的，这需要适当的介质参数的空间色散。这种媒质迫使在原始坐标系中运动的电磁波表现得就像它们在变换后的坐标系中传播一样。从而为设计具有优越功能的先进电磁器件提供了一种新的强有力的技术。坐标变换可以用于压缩、扩展、弯曲或扭曲空间，使隐形斗篷、场集中器、完美透镜、光束移位器等的设计成为可能，这可能会给人类生活的各个领域带来进步。这些器件的实现依赖于创造具有规定的电磁特性的介质的可能性，特别是定向折射率，以提供具有超光速相速度的波传播和法向的高折射率，以引起波沿曲线路径的运动。最初，由微小的金属谐振器组成的人造超材料(MMS)被选作构建转化介质。然而，也遇到了一些严峻的挑战，如工作频带极窄，金属元素损耗高。提出的方法是使用介电光子晶体来克服MM介质的这些主要限制。该项目将允许研究生和本科生，特别是工程专业的女性，参与EM的理论和实验研究。外展活动包括面向K-12学生的几个青年项目的讲座和动手项目。技术描述：该项目将为基于工程光子晶体(PHC)的媒体开发一个平台，使其不受超材料媒体的主要限制。该项目旨在控制波在介质中沿正交晶体方向的传播，并依靠自准直现象来制定基于TO的折射率处方。为了实现超光速折射率和普通折射率沿晶体所需轴线的定向色散，需要适当地改变其晶格参数。通过用优化尺寸的晶体碎片构建介质，将提供对折射率值的精确控制。将使用平行板波导室进行微波实验，以记录波的传播并验证计算结果。早期开发的制造低损耗光子晶体的技术将有助于实现实际器件。这项跨学科的研究将整合电磁学、物理学、光学和材料科学的概念；采用全波计算建模和设计；设计复杂材料建筑；掌握复杂结构的表征技术。该项目将通过开发新的媒体工程方法和解决基本问题，包括整合自准直，为TO开辟新的前景。这项研究将整合电磁学、物理学、光学和材料科学的概念，并将促进PHCS的潜力。

Title: Novel media for transformation optics using dielectric photonic crystalsNon-Technical Description: Transformation optics (TO) is based on coordinate transformations, which require proper spatial dispersions of the media parameters. Such media force electromagnetic (EM) waves, moving in the original coordinate system, to behave as if they propagate in a transformed coordinate system. Thus TO introduces a new powerful technique for designing advanced EM devices with superior functionalities. Coordinate transformations can be derived for compressing, expanding, bending, or twisting space, enabling designs of invisibility cloaks, field concentrators, perfect lenses, beam shifters, etc., that may bring advances to various areas of human life. Realization of these devices depends on the possibility of creating media with prescribed EM properties, in particular, directional refractive indices to provide wave propagation with superluminal phase velocities and high refractive indices in the normal direction to cause wave movement along curvilinear paths. Originally, artificial metamaterials (MMs) composed of tiny metallic resonators were chosen for building transformation media. However, a number of serious challenges were encountered, such as extremely narrow frequency band of operation and the high losses in metal elements. The proposed approach is to use dielectric photonic crystals to overcome these major limitations of MM media. This project will allow graduate and undergraduate students, especially women in engineering, to participate in theoretical and experimental EM research. Outreach activities include lectures and hands-on projects in several youth programs to K-12 students.Technical Description: This project will develop a platform for engineering photonic crystal (PhC)-based media that are free from the major limitations of metamaterial media. The project aims to control wave propagation in media along orthogonal crystallographic directions and relies upon self-collimation phenomena at formulating TO-based prescriptions for refractive indices. For realizing directional dispersions of both superluminal and ordinary indices along desired axes of crystals, proper variations of their lattice parameters will be used. Accurate control of index values will be provided by building the media from crystal fragments with optimized dimensions. Microwave experiments using a parallel-plate waveguide chamber will be performed to record wave propagation and to verify computational results. Technologies developed earlier for fabricating low-loss PhCs will help to implement the practical devices. This interdisciplinary research will integrate electromagnetics, physics, optics, and materials science concepts; employ full-wave computational modeling and design; engineer complex materials architectures; and master characterization techniques for complex structures. The project will open up perspectives for TO by developing new approaches for media engineering and by solving fundamental problems, including integration of self-collimation. This research will integrate electromagnetics, physics, optics, and materials science concepts and will advance the potential of PhCs.