Bøger i Synthesis Lectures on Electromagnetics serien

The transfer-matrix method (TMM) in electromagnetics and optics is a powerful and convenient mathematical formalism for determining the planewave reflection and transmission characteristics of an infinitely extended slab of a linear material. While the TMM was introduced for a homogeneous uniaxial dielectric-magnetic material in the 1960s, and subsequently extended for multilayered slabs, it has more recently been developed for the most general linear materials, namely bianisotropic materials. By means of the rigorous coupled-wave approach, slabs that are periodically nonhomogeneous in the thickness direction can also be accommodated by the TMM. In this book an overview of the TMM is presented for the most general contexts as well as for some for illustrative simple cases. Key theoretical results are given; for derivations, the reader is referred to the references at the end of each chapter. Albums of numerical results are also provided, and the computer code used to generate these results are provided in an appendix.

The fundamental optical excitations that are confined to a metal/dielectric interface are the surface plasmon polaritons (SPPs), as described by Ritchie. SPPs can be referred to as electromagnetic excitations existing at an interface between two media, of which at least one is conducting. Investigating spoof plasmons in a semiconductor is becoming an increasingly active area of research. The field of plasmonics deals with the application of surface and interface plasmons. It is an area in which surface plasmon-based circuits merge the fields of photonics and electronics at the nanoscale. Recently, an idea of engineering surface plasmons at lower frequencies was suggested. It was concluded in that the existence of holes in the structure can lower the frequency of existing surface plasmons. Thus, by cutting holes or grooves in metal surfaces, it is possible to take concepts such as highly localized waveguiding and superfocusing to lower frequencies, particularly to the THz regime, where plasmonics could enable near-field imaging and biosensing with unprecedented sensitivity. It is the main reason to use the terminology "e;spoof surface plasmons"e; for the bound surface waves propagating along the perforated structures. The book's title Spoof Plasmons demonstrates that it is devoted to exhibiting the current state of the art of the dynamic and vibrant field of photonic metamaterials reaching across various disciplines, suggesting exciting applications in chemistry, material science, biology, medicine, and engineering.

Thin-film solar cells are cheap and easy to manufacture but require improvements as their efficiencies are low compared to that of the commercially dominant crystalline-silicon solar cells. An optoelectronic model is formulated and implemented along with the differential evolution algorithm to assess the efficacy of grading the bandgap of the CIGS, CZTSSe, and AlGaAs photon-absorbing layer for optimizing the power-conversion efficiency of thin-film CIGS, CZTSSe, and AlGaAs solar cells, respectively, in the two-terminal single-junction format. Each thin-film solar cell is modeled as a photonic device as well as an electronic device. Solar cells with two (or more) photon-absorbing layers can also be handled using the optolelectronic model, whose results will stimulate experimental techniques for bandgap grading to enable ubiquitous small-scale harnessing of solar energy.

Electromagnetic metamaterials are a family of shaped periodic materials which achieve extraordinary scattering properties that are difficult or impossible to achieve with naturally occurring materials. This book focuses on one such feature of electromagnetic metamaterials-the theory, properties, and applications of the absorption of electromagnetic radiation. We have written this book for undergraduate and graduate students, researchers, and practitioners, covering the background and tools necessary to engage in the research and practice of metamaterial electromagnetic wave absorbers in various fundamental and applied settings. Given the growing impact of climate change, the call for innovations that can circumvent the use of conventional energy sources will be increasingly important. As we highlight in Chapter 6, the absorption of radiation with electromagnetic metamaterials has been used for energy harvesting and energy generation, and will help to reduce reliance on fossil fuels. Other applications ranging from biochemical sensing to imaging are also covered. We hope this book equips interested readers with the tools necessary to successfully engage in applied metamaterials research for clean, sustainable energy. This book consists of six chapters. Chapter 1 provides an introduction and a brief history of electromagnetic wave absorbers; Chapter 2 focuses on several theories of perfect absorbers; Chapter 3 discusses the scattering properties achievable with metamaterial absorbers; Chapter 4 provides significant detail on the fabricational processes; Chapter 5 discusses examples of dynamical absorbers; and Chapter 6 highlights applications of metamaterial absorbers.