Photonics Dictionary

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 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.

The normal condition of vision where an object at infinity is in sharp focus with the eye lens in a neutral or relaxed state.

Magnification that is above the level of maximum useful magnification and does not contribute useful resolving power. In a visual telescope, empty magnification is any in excess of 20 D, where D =...

In photography, the layer of light-sensitive material (usually a suspension of silver halide crystals) that coats the film or plate.

The sensitivity of a photographic emulsion when exposed to light, provided that the film is developed through a standard process.

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 arc lamp whose carbon electrodes are enclosed in a transparent chamber, resulting in an arc that is steadier, lasts longer and emits more ultraviolet radiation.

A laser or laser system positioned within an enclosure to prevent dangerous optical radiation from leaving the enclosure.

End-fire coupling refers to a method of coupling energy into or out of a waveguide, transmission line, or antenna, where the electromagnetic waves are directed primarily along the axis or direction...

An endoscope is a medical device used for visualizing and examining the interior of hollow organs, body cavities, or confined spaces within the body. It consists of a flexible or rigid tube equipped...

The photographing of objects within generally inaccessible areas using endoscopes with camera attachments.

The energy in a medium per unit volume.

A laser that distributes its output power among two, three or four optical fibers simultaneously.

A hologram produced by a pair of radiation beams, each carrying information.

The occurrence of very large rotations in transparent materials at weak magnetic fields as predicted in the classical dispersion theory. This effect was discovered by Mavaluso and Corbino in 1898 in...

An image processing device that displays pseudocolor images by assigning colors to the gray scales according to look-up tables defined by the user.

Enhanced picture archiving and communication system (PACS) display (ePAD) is a software tool used in medical imaging to view, manipulate, and analyze radiological images, such as x-rays, CT scans,...

A type of laser pulsing with high laser power at the beginning of the pulse.

The line from a spark or other very hot source that has greater intensity than that of a line produced by an arc or flame source. Also called an enhanced line.