Toroidal Metamaterials: Fundamentals, Devices, and Applications

1. Introduction and Overview

1.1. The History of Light and Matter

1.2. The History of Light-Matter Interactions

1.3. The Discovery and Properties of Artificial Media

References

2. Classical Electromagnetics

2.1. Fundamental Principles of Static Electromagnetics

2.1.1. Coulomb's and Gauss's Laws

2.1.2. Biot-Savart and Amp鋨e's Laws

2.1.3. The Lorentz Force

2.2. Equations for Static Fields

2.3. Fundamental Principles of Dynamic Electromagnetics

2.3.1. Maxwell's Equations in Vacuum

2.3.2. Maxwell's Equations in Macroscopic Media

2.4. The Electric Dipole

2.4.1. Multipole Expansion and Electric Multipoles

2.4.2. The Dipole and Quadrupole Potentials

2.5. Magnetic Multipoles

2.6. Unconventional Multipoles

2.6.2. Dynamic Toroidal Multipoles

2.6.3. Dynamic Anapoles

References

3. Expansion of Electromagnetic Multipoles

3.1. Debye Potentials

3.2. Electromagnetic Radiations of Toroidal Solenoids

3.2.1. The Multipole Decomposition

3.2.2. The Dynamic Toroidal Multipoles

3.2.3. The Long Wavelength Regime

3.2.4. The Magnetostatic Regime

3.2.5. The Point Source Regime

References

4. Physical Mechanism Behind the Toroidal Multipoles

4.1. Defining the Problem

4.1.1. Potentials and Fields of a General Source

4.1.2. Fields at Far Distances

4.2. Radiation Intensity

4.3. Angular Momentum Loss.

4.4. Recoil Force

4.5. The Connection between Cartesian and Spherical Components of the First Multipoles

References

5. Toroidal Excitations in Metamaterials

5.1. Toroidal Excitations in 3D Artificial Media

5.2. Toroidal Multipoles in Planar Artificial Media

References

6. Toroidal Metadevices

6.1. Photodetection: Enhancing the Responsivity Performance

6.2. Nonlinear Lasing: Deep Ultraviolet Source

6.3. Immunosensors: Beyond Conventional Detection Limits

6.4. Plexciton Dynamics: Intensifying Ultrastrong Coupling

References