Photonics Dictionary: E

A technique that uses the passage of an electrical current through a recording medium to produce a permanent image on that medium.

A device that permits only electrons within a narrow velocity range to pass through it, while rejecting those above and below.

The effect produced by electrical charges or fields alone, without interaction with magnetic influence.

The deflection of an electron beam by the action of an electrostatic field that has a component perpendicular to the direction of the beam.

The use of an applied electrical field to focus a cathode-ray tube's electron beam.

A nonmagnetic instrument utilizing an electrofocus and deflection tube with a photocathode for imaging purposes. The optical image is converted into a photoelectric output at the photocathode and is...

The electrical distribution that serves to influence an electron beam in the same way that an optical lens affects a light beam.

An instrument used to print an optical image on a specially treated paper. Light and dark portions of the original image are illustrated by electrostatically charged and uncharged portions of the...

A process used in document copying and printing that involves the visible rendering of an invisible electrostatic image on a photoconductive material by its treatment with oppositely charged pigment...

Information storage on a dielectric medium that represents the data as those spots on the medium having electrostatic charges, forming an observable record of the data.

A camera that records its images electrostatically on plastic tape; used in situations where radiation would have an adverse effect on regular photographic film.

An image intensifier that uses electrostatics to amplify and focus the electronic image.

The recording of patterns by the production and use of latent electrostatic charge patterns. See electrostatic process.

Elastic deformation of a dielectric caused by volume force when the dielectric is placed in an inhomogeneous electric field.

A common form of high-precision, ceramic-based actuator capable of moving and measuring at the nanometer level.

An electrowetting display (EWD) is a type of electronic display technology that utilizes the principles of electrowetting to control the behavior of colored oil droplets on a hydrophobic surface....

A spectrometer equipped with polarizing prisms and retardation plates that is used in the analysis of elliptically polarized light, mostly in the study of thin, evaporated films.

Ellipsometry is an optical technique used to characterize the properties of thin films and surfaces. It is based on the measurement of changes in the polarization state of light reflected or...

A light beam whose electric vectors are broken into two elements of unlike amplitudes that are perpendicular to each other and that differ in phase by values other than 1, 3/4, 1/2, 1/4, etc.,...

The quality of asymmetrical intensity distribution in a laser beam, as opposed to a circular distribution.

The term "embedded laser" typically refers to a laser device that is integrated or embedded into a larger system or structure. In this context, "embedded" implies that the laser is an integral part...

Embedded vision refers to the integration of computer vision technologies into various embedded systems, devices, or machines. Computer vision involves teaching machines to interpret and understand...

A hologram imprinted on plastic or another medium; e.g., those commonly found on credit cards.

In optics, the light ray leaving a medium in contrast to the entering or incident ray.

A natural abrasive, produced from corundum in grades ranging from rough to fine, used in the grinding and lapping of glass.

The line or lines emitted by an element when its radiation particles travel from one energy level to another.

A type of electron microscope in which the specimen also serves as the cathode source.

Thermal emission caused by the unity in absorption bands that must be discriminated when calculating radiation intensity of any celestial object.

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...

The emissivity of a body times the emissive power of a blackbody at the same temperature. For a blackbody, it is the total radiation per unit area of radiating surface.

The ratio of an object's radiance to that emitted by a blackbody radiator at the same temperature and at the same wavelength.

A computer-generated routine for achieving true-temperature readings in thermal infrared imaging systems.

The use of a material's emissivity to measure absorption. It is useful as an absorption loss measurement technique, since at thermal equilibrium, emittance is equal to absorptance.