# 21st Century Electromagnetics

## Video Lectures

Displaying all 22 video lectures.
 Lecture 1 Play Video Preliminary topics in EMThis is a simple lecture reviewing some very basic electromagnetic principles. It also covers construction of derivative operators on scalar (single function) grids with Neuman boundary conditions. Prerequisite Lectures: Basic EM Theory and "Computational Electromagnetics" Lecture 2 Play Video Lorentz and Drude modelsThis lecture introduces the student to the Lorentz model which describes the dielectric response of materials and Drude model which describes metals. The lecture gives physical insight as to why materials have a dielectric and magnetic response and some implications of this. Prerequisits: Mechanics and Electromagnetics Lecture 3 Play Video Nonlinear and anisotropic materialsThis lecture builds onto the previous to introduce nonlinear and anisotropic materials. The discussion on nonlinear materials is brief, but the discussion on anisotropic materials covers tensors, tensor rotation, Maxwell's equations in anisotropic media, and index ellipsoids. Prerequisits: Mechanics, Electromagnetics, and Linear Algebra Lecture 4 Play Video Transmission lines in anisotropic mediaThis lecture briefly introduces RF transmission lines and what happens when they are embedded in anisotropic media. The main objective of this lecture to model these devices using the finite-difference method. Prerequisite Lectures: Lecture 3 and "Computational Electromagnetics" Lecture 5 Play Video Coupled-mode theoryThis lecture steps the student through coupled-mode theory using perturbation analysis. The primary objective, however, is to illustrate and explain coupled mode theory from a picture/qualitative perspective. Lecture 6 Play Video Coupled-mode devicesThis lecture builds on Lecture 5 to introduce the student to a variety of devices that operate based on coupled-mode theory. Devices include coupled-line filters, Bragg gratings, long period gratings, thin film optical filters, and more. Prerequisite Lectures: 5 Lecture 7 Play Video Theory of periodic structuresThis lecture introduces the math underlying periodic structures and then discusses electromagnetic waves inside periodic structures. Prerequisite Topics: Electromagnetics and "Computational Electromagnetics" Lecture 8 Play Video Calculation examples of periodic structuresThis lecture provides two step-by-step examples of performing calculations on periodic structures. This includes calculating direct and reciprocal lattice vectors, constructing the Brillouin zone and irredicuble Brillouin zone, band diagrams, and isofrequency contours. Prerequisite Lectures: 7 Lecture 9 Play Video Diffraction gratingsThis lecture builds on prior lectures to describe diffraction gratings and associated devices. The grating equation and diffracted modes are presented. The lecture ends by showing how patterned fanout gratings are designed using the Gerchberg-Saxton algorithm. Prerequisite Topics: Lecture 7, Electromagnetics, and "Computational Electromagnetics" Lecture 10 Play Video Subwavelength gratingsThis lecture discussed the use of gratings when the period is much smaller than the wavelength and only the zero-order mode exists. Such media are artificially anisotropic metamaterials and can be used for antireflection, wave plates, polarization control, and more. Prerequisite Lectures: 7 and 9 Lecture 11 Play Video Guided-mode resonanceThis lecture introduces devices based on guided-mode resonance. The lecture includes a description of the physics, illustrates how various parameters affect the response, describes a simple design procedure with examples, and highlights some of the main applications. Prerequisite Lectures: 7 and 9 Lecture 12 Play Video Introduction to engineered materialsThis lecture introduces the student to "engineered materials." This is an all-encompassing term that includes ordinary materials, mixtures, metamaterials, and photonic crystals. While ordinary materials are discussed very briefly, the lecture focuses on mixtures and the effects of particle shape, etc. Metamaterials and photonic crystals are introduced, but are discussed in later lectures. Prerequisite by Topic: Electromagnetics Lecture 13 Play Video MetamaterialsThis lecture introduces the student to metamaterials. It categorizes metamaterials into resonant and nonresonant types. It is not a comprehensive lecture on the subject, but attempts to give the student an intuitive understanding of the subject. Topics include effective media metamaterials, left-handed metamaterials, anisotropic metamaterials, and hyperbolic metamaterials. Lecture 14 Play Video Photonic crystals (band gap materials)This lecture builds on previous lectures to discuss the physics and applications of photonic crystals (electromagnetic band gap materials). A basic definition is given and then the physics leading to the band gap is discussed along with the conditions for complete band gap are outlined. Dispersion engineering in photonic crystals is discussed along with self-collimation. Prerequisite Lectures: 7 and 8 Lecture 15 Play Video Homogenization and parameter retrievalThis lecture describes the methods used to determine the effective electromagnetic properties of engineered materials. The basic concept is presented along with a survey of methods. Lecture 16 Play Video Transformation ElectromagneticsThis lecture introduces transformation electromagnetics, also called transformation optics. It outlines the procedure, provides MATLAB code, and steps the student through several examples. The lecture ends with a survey of different applications. Lecture 17 Play Video Holographic lithographyThis lecture describes holographic lithography and how to design four beams whos interference pattern can be used to fabricate any of the 14 Bravais lattices. The lecture serves as good practice of the relationship between wave vectors, grating vectors, and reciprocal lattice vectors. Lecture 18 Play Video Synthesis of spatially variant latticesThis lecture describes an algorithm to spatially vary a periodic structure. That is, attributes such as orientation of the unit cells, lattice spacing, and fill fraction can be made to vary as a function of position. The overall lattice is kept smooth, continuous, and defect free. Undesired deformations are minimized. Lecture 19 Play Video Interfacing MATLAB with CADThis lecture deviates from electromagnetics and discusses the interface between MATLAB and CAD, which is presently very crude. Creating and reading text files is discussed following by STL file reading and writing. The lecture goes on to describe how to create geometries in MATLAB and export them to CAD. Lecture 20 Play Video Frequency selective surfacesThis lecture introduces the student to frequency selective surfaces. These are planar structures that filter certain frequency bands. Classifications and comparisons are given to provide an intuitive feel to the workings of a frequency selective surface. Lecture 21 Play Video Surface wavesThis lecture introduces the student to the concept of surfaces waves. It describes why they exist identifies a number of different types of surfaces waves. Extra detail is provided on ways to couple energy into surface waves, surface plasmons, and Dyakonov surface waves. Lecture 22 Play Video Slow wavesThis lecture introduces slow waves. It starts by describing phase, group, and energy velocities from which the cause of slow waves is discussed. Media producing slow waves are dividing into resonant structures and pure material structures. An array of examples are given for each.