| Metamaterial (MTM), as artificial materials composed of Meta-atoms, has not only attracted many research interests in the past fifteen years, but also changed some basic understanding of electromagnetic theory. The concept of MTM has originated from negative refractive index materials, but it actually established a platform for people to manipulate electromagnetic waves more freely. This thesis will just begin from here by reviewing some early efforts on negative refraction and MTM in Section1, Chap-ter1. After this, the author will give a detailed introduction to the building block of MTM, namely Meta-atoms. Some fundamental micro-structures, and how to use them to achieve fantastic optical properties will be presented in Section2, Chapter1. Since how to form Meta-atoms into bulk material is crucial in MTM, so we will discuss this issue, we call it "order", in Section3, Chapter1. To illustrate order more clearly, we will focus on Transformation Optics and Meta-surface which are hot topics in the past few years. Moreover, accompanied with the improvement of fabrication technology and the smaller size, quantum effects will lead optical properties of MTM dramatically deviated from classical theory. This attracts many interests in the past two years be-cause both theoretical treatments and experimental measurements are unsophisticated. So the author will introduce this field in Section4. Chapter1.We will begin our research on how to use MTM to manipulate electromagnetic waves in Chapter2. For a small antenna placed on a metamaterial ground plane ver-tically or horizontally, we analyzed the conditions under which the antenna emission-s are highly directional in Section2, Chapter2. We found through finite-difference time-domain (FDTD) simulations that a previously discovered directional emission phenomenon can be explained by our theory for the horizontal antenna case. For the vertical antenna case, we employed FDTD simulations to design a realistic metamate-rial ground plane with desired reflection phase properties, and performed microwave experiments to verify its ability to support directional emissions in Section3, Chapter2.Next, we will focus on how to manipulate optical force by using MTM in Chapter3. For chiral particles, we discovered a new mechanism which is different for previous Mie scattering mechanism, to achieve Optical Pulling Force (OPF). We analytically derive time averaged optical force formula, and give out the conditions under which optical force on chiral particles could be negative in Section2, Chapter3. Finally, we employ multiple scattering method to design realistic structures, and OPF is verified by numerical calculations in Section3, Chapter3.Further more, we will study graphene-based MTM in Chapter4. Mapping a planar conductor with arbitrary electronic band structure (e.g., linear or parabolic) to a slab of bulk medium exhibiting the same optical responses, we formulated an equivalent-medium approach to study the optical properties of metamaterials (MTMs) made by patterning such a planar conductor, particularly for the graphene system in Section2, Chapter4. The theory was applied to study various graphene-based MTMs in Section3and4, Chapter4, with calculation results on one particular system (with no adjustable parameters) agreeing well with available experiments.In the end, we will draw our conclusions and make some perspective on the further work. The thesis has studied some topics in MTM field, but due to the complicated MTM and the limitations of author’s knowledge, it is not easy to do a more deep study of the entire field. Therefore the works in this thesis are skin-deep, but I hope it can attract valuable comments from others in order to supply the gap between the MTM research in China and that in the world.
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