Designing Electromagnetic Devices Based On Transformation Optics And Anisotropic Metamaterials

Metamaterials show many novel properties which are not found in natural materials so that they have been widely applied to new EM device designation and improvement.Meanwhile,the appearance of Transformation Optics provides us a method to flexibly control the EM wave.When combined with metamaterials,people could realize some fascinating devices like invisible cloak and optical illusion device and so on.In this paper,we discussed the Transformation Optics theory and anisotropic metamaterials.Based on the analysis,we designed several new EM devices.The main achievements include:1.We discussed the diffraction limit of Graded Index(GRIN)lens,and designed a super-GRIN lens based on Transformation Optics which could overcome the diffraction limit and improve the resolution of the original lens.The mentality of designation is to apply a compression transformation to the graded index material.We adopt two kinds of transformations to realize super-GRIN lenses and validated them through full wave numerical simulation.2.We designed a Maxwell fisheye lens with a cloaked center area.It could realize EM wave coupling across obstacles inside the cloak.EM wave incidents from arbitrary direction could skirt the central area and focus to the other side.Furthermore,we applied such idea to realize Surface Plasmon Polaritons(SPPs)wave coupling using the cloaking Maxwell fisheye lens.3.We theoretically investigated the infinity anisotropic metamaterials,explained why they could suppress diffraction.Deep subwavelength wave could diffraction-freely propagate in infinity anisotropic metamaterials.Further through proper designation and combination of infinity anisotropic metamaterials,we realized a subwavelength beam splitter,a subwavelength beam compressor and a transformation of a line source into specific directional subwavelength beam irradiator.We performed full-wave simulations to validate our designations and realized the infinity anisotropic material with the multilayer structure of normal materials.4.We discussed the propagation issue of SPP wave.SPPs wave is tightly confined to the metal-dielectric interface,however when there are some discontinuous structures,like a gap,an obstacle,or the uneven surface,SPPs wave will suffer severely scattering.This greatly limits the application of SPPs circuits or devices.Infinity anisotropic metamaterials could suppress the diffraction of SPPs wave.We applied the anisotropic metamaterials to realize the coupling of SPPs wave across the discontinuous structures.Full-wave simulations have been performed to validate our results.