Photonics Dictionary: E

A characterization of the throughput performance of data storage systems; the EDR is the total of data retrieved divided by the total time it takes to retrieve it, expressed as megabytes per second.

The organic inclusion in quartz crystal that forms delicate films and microspheres and that shows a maximum absorption at 450 nm.

A refracting telescope that uses a prism to bend the line of sight 90°.

An electrically excited laser having carbon monoxide as the lasing material and in which lasing occurs in a partial inversion between adjacent, vibrational fields. Vibrational energy is cycled...

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 lamp that uses the transmission of an electric current through a gas or vapor to produce illumination. Neon, mercury and argon lamps are examples of electric-discharge lamps.

The effect whereby a light beam is deflected by a birefringent prism when its polarization is changed by voltage applied to an electro-optical crystal through which the beam passes. The deflection of...

An electro-optic deflector is a device that can change the direction of light beams using an electric field. It operates based on the electro-optic effect, which involves the modulation of the...

A device that detects radiation by utilizing the influence of light in forming an electrical signal. It may be a phototube; a photoconductive, photovoltaic or photojunction cell; a phototransistor;...

An electro-optic modulator (EOM) is a device used to modulate the amplitude, phase, or polarization of light waves using an external electrical signal. Electro-optic modulation is a fundamental...

A radar system that uses electro-optic rather than microwave instrumentation and methods to perform its acquisition and tracking functions.

A type of optical modulator with potential application in optical switching and displays, in which applied voltage causes a change of interfacial tension between mercury and an electrolyte, varying...

Type of solid-state display tube in which the readout surface is coated with a material that changes color when positively or negatively charged.

A device consisting of an airtight quartz tube that holds the material to be analyzed. When a high-frequency electrostatic field, generated by microwaves, is applied to the tube, it emits energy of a...

The study of the generation of electromagnetic power by radiation from high-energy beams.

A technology that uses electrically activated holograms stored within specially developed crystals to route information in the form of lightwave signals from one optical fiber to another within and...

The nonthermal conversion of electrical energy into light in a liquid or solid substance. The photon emission resulting from electron-hole recombination in a PN junction is one example. This is the...

Conduction of an electric current through a chemical compound in its natural state, solution or as a molten, to decompose the compound.

Developing a photographic image by means of an applied electric field. The methods used include electrolysis and photoconductive systems.

A high-speed shutter, similar to a Kerr cell, that uses the birefringence produced in a liquid during the passage of an electric current through it to change the liquid's optical transmission...

The ability of a device to operate without electromagnetically interfering with the operation of nearby equipment and without suffering disturbances from the electromagnetic fields in its designated...

The distribution of electromagnetic fields in a given area. The units are volts per meter, watts per meter squared and joules per meter cubed.

An electron lens consisting of a homogeneous axial electric field and a magnetic field used in high-quality image tubes for high modulation transfer function and small geometrical distortion...

Radiation emitted from vibrating charged particles. A combination of oscillating electrical and magnetic fields that propagates through otherwise empty space with the velocity of light. This constant...

The total range of wavelengths, extending from the shortest to the longest wavelength or conversely, that can be generated physically. This range of electromagnetic wavelengths extends practically...

An electromagnon is a quasiparticle excitation that combines aspects of both magnetism and electric polarization in a crystal lattice. Specifically, it refers to a collective excitation of spins and...

A charged elementary particle of an atom; the term is most commonly used in reference to the negatively charged particle called a negatron. Its mass at rest is me = 9.109558 x 10-31 kg, its charge is...

A stream of electrons emitted by a single source that move in the same direction and at the same speed.

The bending of an electron stream that occurs when the stream travels through a medium such as very thin metal foil.

An electrostatic device that uses an electric potential barrier to allow the transmittance of electrons at or above a set level of energy while stopping the passage of those below it.

A cathode-ray tube that increases the brightness or size of an image or forms a visible image from invisible radiation. The focal plane for the optical image is a large, light-sensitive, cold...

An electric field produced to influence an electron stream much in the same manner that a lens affects a light beam.

The photographic recording of images produced by the electrons from an electron microscope. The electron beam carries the images through an array of three lenses, and an enlarged electron image is...

A device utilizing an electron beam for the observation and recording of submicroscopic samples with the aid of photographic emulsions or other short-wavelength sensors. With the electron microscope,...

An electron instrument used to reflect an electron beam totally.

An EMCCD (electron-multiplying charge-coupled device) camera is a type of scientific camera specifically designed for low-light imaging applications that require high sensitivity and fast readout...

A CCD device in which a solid-state electron multiplying register has been added to the end of the normal serial register. The electron multiplying register allows weak signals to be multiplied...

The control of free electron movement through the use of electrical or magnetic fields, and use of this electron movement in research investigation of electronic diffraction phenomena, directly...

The theory and interpretation of spectra produced by the electron emissions of substances after their irradiation by x-rays.

An instrument that serves to produce an enlarged electron image on a fluorescent screen by focusing an infrared image of a distant object upon a photosensitive cathode.

Approximation of a system of thermal equilibrium formed by the distribution of the kinetic energies of electrons in a gas discharge to which a temperature value is frequently ascribed. The average...

A method of erasable optical data storage in which information is stored by visible light, then read by illumination with an infrared source that returns trapped electrons to their ground state....

The use of a tightly focused beam of electrons to drill minute holes in substances. The drilling is accomplished by the evaporation of the material in the desired circumference by the intense heat of...

1. A device generally used in a cathode-ray or camera tube to emit a stream of electrons moving at uniform velocity in a straight line. It consists of an emitting cathode and an anode, with an...

A small xenon-filled tube with metal electrodes fused into the ends. The gas flashes brilliantly when a condenser is discharged through the tube. The duration of the flash is primarily dependent upon...