Glossary
Nano-optics / Nanophotonics
Study of the behavior of light on the nanometer scale. It is considered as a branch of optical engineering which deals with optics, or the interaction of light with particles or substances, at deeply subwavelength length scales.
General reading: Principles of Nano-Optics by L. Novotny and B. Hecht
Nearfield optics
Branch of optics that considers configurations that depend on the passage of light to, from, through, or near an element with subwavelength features, and the coupling of that light to a second element located a subwavelength distance from the first.
Metallic nanostructures/ nanoparticles
Metallic nanoparticles and nanostructures are typically ranging from a few nanometers to a few hundreds of nanometers in size. In this size regime, noble metals such as gold, silver, copper, and platinum sustain strong collective oscillation modes of their conduction electron gas when immersed in an external electromagnetic field. This collective oscillation, called localized surface surface plasmon plays a key role in nanophotonics.
Plasmon / Plasmonics
[Quasiparticle / elementary excitation] Imcompressible, irrotational, collective oscillations of the free (conduction) electron gas. In nanoscale objects one talks about Localized Surface Plasmons (LSP). Plasmons can couple with a photon to create another quasiparticle called a polariton
General Reading: Plasmonics: Fundamentals and Applications by S.A. Maier
Exciton / Plexcitonics
[Quasiparticle / elementary excitation] An Exciton is the state of an electron-hole pair bound to each other by the electrostatic Coulomb force. It is an electrically neutral quasiparticle that exists in insulators, semiconductors and in some liquids.
Plexcitonics is the study of the electromagnetic interaction between a Plasmon and an Exciton.
Phonon / Acousto-Plasmonics / Plasphonics
[Quasiparticle / elementary excitation] A Phonon is a quantized elastic wave propagating in an cystral lattice. This elastic wave can be longitudinal or transverse to the planes of atoms. When looking at the phonon dispersion in a crystral, these crystal vibrations can be sorted into two categories namely acoustic phonons (or acoustic vibrations) at low energy and optical phonons at high energy. Typical phonon dispersion diagram then display combinations of longitudinal and transverse acoustic and optical branches (LA, TA, LO, TO). When the phonons are present in metallic nanoparticles they interact with the surface plasmons sustained by the metallic nanoparticle. Plasphonics (or acousto-plasmonics) is the study of the interaction between a Plasmon and a Phonon (or Vibration).
More on vibrations: Dr. Lucien Saviot
Maxwell's Equations
Electrodynamic properties of matter are governed by a set of four coupled equations named after James C. Maxwell (On Physical Lines of Force, 1861-1862 and A Dynamical Theory of the Electromagnetic Field, 1864). In absence of external charge and current, Maxwell's equations, in their differential form and in SI units, have the form:
[Gauss' law says that the total of the electric flux out of a closed surface is equal to the charge enclosed divided by the permittivity. In absence of charge (no term on the right side of this equation), there's no electric field.]
[Gauss' law for magnetism says that in a given volume the sum of the magnetic field lines going in equals the sum of the magnetic field lines going out. In other words the magnetic field lines must be closed loops.]
[Faraday's law shows how the electric and magnetic fields are related each other. A changing magnetic flux induces an electric field.]
[Ampère's law says that a magnetic field around an electric current is proportional to the electric current which serves as its source]
where E, D, H, and B are the electric field, electric displacement, magnetic field, and magnetic induction, respectively.
It has to be noticed that this vector notation of Maxwell's equations has been later introduced by Oliver Heaviside.
The 8 original equations were (click to enlarge):
General Reading: Classical Electrodynamics by J.D. Jackson
HPC
High performance computing is the use of massively parallel processing for running advanced numerical applications and programs efficiently and quickly. HPC systems range from stand alone servers, to clusters of servers, to supercomputers. HPC allows scientists to tackle challenging and sophisticated problems.[More information on UTSA's HPC resource here]
Simulations / Modeling
Use of numerical/simulation methods (e.g. FDTD, FEM, DDA, BEM) to solve physical/mathematical problem. In Nano-photonics, these numerical tools are needed for solving Maxwell's equations.
Mie Theory
Mie solutions to Maxwell's equations (also known as the Lorenz–Mie solution, the Lorenz–Mie–Debye solution, or Mie scattering) describes the scattering of electromagnetic radiation by a sphere. Mie theory provides an exact, analytical solution to this scattering problem. [Mie calculation widget available here]
FDTD
The Finite-Difference Time-Domain is a numeral method used to solve Maxwell's equations in the time-domain. The spatial domain is discretized in volume elements (Yee cell's). [Lumerical FDTD Solutions package and Meep package]
FEM
The Finite Element Method is a numeral method used to solve Maxwell's equations in the frequency-domain. The physical structure is discretized by volume elements. [Comsol Multiphysics package]
DDA
The Dipole Discrete Approximation is a numeral method used to solve Maxwell's equations in the frequency-domain. The physical structure is described in terms of electric point dipoles. [DDSCAT package]
BEM
The Boundary Element Method is a numeral method used to solve Maxwell's equations in the frequency-domain. Contrary to the FEM, only the boundaries of the physical structure (surfaces) is discretized. [MNPBEM Toolbox]