Photonics Dictionary

In image processing, the location of edges by employing templates that respond to the first or second derivative of gray-scale intensity in the neighborhood of each pixel.

Process for growth of solar cells that results in rectangular shapes consisting of many interconnected cells in a series or series-parallel arrangement. EFG cells show increased efficiency with...

An edge-emitting light-emitting diode is a type of LED structure where light emission occurs primarily along the edge of the semiconductor chip rather than from the surface. Edge-emitting LEDs are...

A color filter, generally used in photography, to emphasize certain color tones and to modify others in a picture for a more dramatic image. A blue effect filter, for example, darkens red and yellow,...

In photoelectric sensing, the portion of the transmitted beam that actually functions in the system; the diameter of the beam that determines the presence or absence of an object by being blocked or...

The color of an object when it is illuminated by a nonisophotic source.

A weight reducing method whereby material from the rear of a reflector is removed leaving a pattern of ribs normal to the surface in an egg-crate pattern.

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.

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°.

Any lamp whose emission of radiant energy is dependent upon the passage of an electrical current through the emissive medium.

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.

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...

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...

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...

The utilization of the light produced when electrical energy is directly converted into light within devices used for visual readout displays or as complex logic-circuit elements. With EL lighting,...

A panel of photoconductive and electroluminescent layers used as either a positive or negative image intensifier, depending on amplitude and phase of its two power supply voltages. The...

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

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...

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...

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...

A maser that relies on the fact that electrons in orbital motion in high-magnetic fields will emit energy at the cyclotron frequency. The transfer of energy is from the bunching of the electrons by...

A special evacuated camera equipped with means for holding a specimen and bombarding it with a sharply focused beam of electrons. A cylindrical film is placed around the specimen to record the...

In a cathode tube, the electrode that serves as a source for electrons.

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...

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...

The photographic recording, and later enlarging, of very thin specimens, using an electron beam to form the image.

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 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...

The deflection of a beam of electrons, at regular intervals, across a cathode-ray tube screen, according to a definite pattern.

A method for detecting vibration amplitudes analogous to image holography, except that the film emulsion is replaced by a television target.

An advanced magnetic device used in x-ray lithography to beam x-rays onto the surface of silicon wafers used for semiconductor circuits.

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.

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...

A method of thin-film deposition in which electrons boiled off a heated cathode are used to melt the coating material. If a multipocket crucible is used, many materials can be processed at the same...