Photonics Dictionary: E

A unit of energy equal to the amount of energy absorbed by one molecule of material undergoing a photochemical reaction, as determined by the Stark-Einstein law.

Three proportional coefficients labeled Am, Bmn, and Bnm, that respectively characterize the rate of spontaneous emission, induced emission, and absorption of radiation by an atom, ion or molecule.

Any material of a macromolecular nature that can stretch at room temperature to more than twice its length and return to approximately its original shape when stress is released.

The use of a krypton laser system for the measurement of small molecules aligned by an electric field, by analyzing the absorption of linearly polarized light.

A spectrum band that is usually found in the visible or the ultraviolet because of the electron transitions taking place within the molecules.

An electron-gun system is an assembly used to generate and control a focused beam of electrons. Electron guns find applications in various fields, including cathode ray tubes (CRTs), electron...

The bands of spectral lines representing the electronic transition in a molecule.

A study of the energies and wavelengths of radiation emitted by atoms and molecules when particular physical conditions are applied to them.

An emission spectrum is a graphical representation or a characteristic pattern of the wavelengths or frequencies of light emitted by a source, such as an atom, molecule, or celestial object. It shows...

Enantiomers are a pair of molecules that are non-superimposable mirror images of each other, similar to left and right hands. They are stereoisomers, meaning they have the same molecular formula and...

An enzyme-linked immunosorbent assay (ELISA) is a laboratory technique used to detect and measure the presence of specific substances, such as antibodies, antigens, proteins, hormones, or other...

Epitaxial deposition is a process used in semiconductor manufacturing and materials science to grow a thin crystalline layer, known as an epitaxial layer, on a substrate. The term epitaxial refers to...

A well controlled thin films technique for growing films with good crystal structure in ultra high vacuum environments at very low deposition rates. Epitaxy methods are well known for the growing of...

Common name for a variety of adhesives used for lens bonding, fiber optic splicing and other photonics applications. The term is actually a prefix denoting the presence of an epoxide group in a...

Coating carried out in a sealed chamber evacuated by a mechanical pump in series with an oil diffusion pump to a pressure less than 10-4 mm of mercury, measured by a vacuum gauge. At such a low...

A contraction of "excited dimer." The term refers to an excited species made by combination of two identical atoms or molecules, one of which is excited and one of which is at a ground...

An excimer laser is a type of ultraviolet laser that emits short pulses of light in the ultraviolet spectrum. The term excimer is derived from excited dimer, reflecting the nature of the gain medium...

The term "excimer," strictly used, refers to excited species made by combination of two identical moieties, atoms or molecules. Excited complexes that do not fall into this category are...

The stationary state of an ion, atom or molecule, above the ground state that is produced by the interaction with the radiation field or another ion, atom or molecule. See ground state.

An exciton is a quasiparticle that represents the bound state of an electron and a hole in a solid-state material, typically a semiconductor or an insulator. In simpler terms, an exciton is a paired...