That branch of spectroscopy that applies to the study of interactions between energy and atomic nuclei. The simultaneous application of a strong magnetic field and the radiation from a radio-frequency source to the nuclei results in transitions...

A gas laser in which the energy-state transitions between vibrational and rotational states of CO2 molecules give emission...

A type of motion-picture camera in which single frames are photographed either automatically at a predetermined rate (as...

The fundamental wavelength standard of time or frequency. An atomic standard, it is properly expressed as 9,192,631,770...

The transition cross section constant coefficient which defines the transition probability of absorption from ground to a...

A glass-ceramic material developed in Russia. Astrosital resembles Zerodur in terms of its ultralow thermal expansion. Other...

The process whereby a quantum mechanical system alters from one energy level to another. During this process, energy is...

Photodynamic inactivation (PDI) is a therapeutic approach that utilizes the combination of light, a photosensitizer, and...

In the context of materials science and semiconductor physics, doping refers to the intentional introduction of impurities...

Anisotropic is a term used to describe a material or substance that exhibits different properties or behaviors in different...

Any system of time measurement that is based on atomic resonances. The transition times between the hyperfine levels of...

One of the types of change in the energy levels of molecules or atoms in a laser that can result in lasing action. Because...

1. The decrease of the absorption (or gain) coefficient of a medium near some transition frequency when the power of the...

An engine in which work is performed by the expansion of a gas at high temperature; heat for the expansion is supplied...

The term perovskite refers to a specific crystal structure commonly found in various materials. Perovskite structures have a...

Laser-mediated gene transfer refers to a technique in molecular biology and genetic engineering that utilizes lasers to...

In a CD-ROM disc, the reflective area between nonreflective pits representing a binary-language "off'' as opposed to...

A quantum cascade laser (QCL) is a type of semiconductor laser that operates based on the principles of quantum mechanics....

A photodetector, also known as a photosensor or photodiode, is a device that detects and converts light into an electrical...

Superresolution refers to the enhancement or improvement of the spatial resolution beyond the conventional limits imposed by...

An energy transition concerned with photons alone.

Luminescence is the emission of light that occurs without the involved substance undergoing a significant increase in...

In semiconductor physics and materials science, the term "III-V materials" refers to compounds composed of elements from...

Trade name for a type of borosilicate glass manufactured by Corning Glass Works, noted for its low coefficient of thermal...

Optical glass refers to a type of glass specifically engineered and manufactured for use in optical components and systems,...

Oscillator device composed of a semiconducting diode in a coaxial resonating cavity. When the biasing current is applied to...

An instrument used to measure expansion of solids, liquids and gases.

Carrier injection refers to the process of introducing charge carriers (either electrons or holes) into a semiconductor...

The transition boundary between P-type and N-type materials in a semiconductor.

A Darlington current amplifier consisting of two separate transistors, of which a phototransistor is the input device.

A multiline laser system refers to a type of laser that is capable of emitting multiple discrete wavelengths or spectral...

Near-infrared spectroscopy (NIRS) is a non-invasive analytical technique that uses the near-infrared region of the...

A surface heat-treating process that produces a highly stressed surface. In case-hardening of glass, a plate of glass is...

Gain-switching is a technique used in lasers to generate short pulses of light by modulating the gain of the laser medium....

A helium-neon (HeNe) laser is a type of gas laser that emits visible red light at a wavelength of 632.8 nm. It operates...

The pattern of microwave field intensity that can be obtained by detecting the minute expansion of a microwave absorber slab...

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

Raman spectroscopy is a technique used in analytical chemistry and physics to study vibrational, rotational, and other...

Spectrum analysis concerned with the spectra formed by transitions in molecules.

In polarization-preserving optical fibers, the element used to induce birefringence. The SAP is highly doped to provide a...

A method of measuring total hemispherical emissivity of the plane surface of a solid that consists of thermally isolating a...

Germanium crystal refers to a crystalline form of the element germanium (Ge), which is a metalloid and semiconductor...

An emission spectrum is a graphical representation or a characteristic pattern of the wavelengths or frequencies of light...

Abbreviated PAI. An imaging modality with a hybrid technique based on the acoustic detection of optical absorption from...

Collisional absorption of energy that occurs in inertial confinement fusion systems when hydrodynamic expansion of the...

A solid-state laser consisting of active atoms or ions of a transition metal, rare-earth metal or actinide, imbedded in a...

A magnon is a quasiparticle representing a quantized spin wave in a magnetic material. In other words, it is a collective...

An infrared detector is a device that is used to detect and measure infrared radiation, which lies beyond the visible...

Gallium nitride-based light-emitting diodes (GaN-based LEDs) are semiconductor devices that emit light when an electric...

A powerful method, referred to as FCS, for determining the average diffusion coefficients of fluorescent molecules in...

Complementary metal-oxide-semiconductor (CMOS) refers to a technology used in the fabrication of integrated circuits,...

A detector cooling device in which a gas under high pressure escapes through an expansion valve in the tank; as the escaped...

A nonradiative transition refers to a process in which an electron or an atom undergoes a change in its energy state without...

A laser, which stands for "light amplification by stimulated emission of radiation," is a device that produces coherent and...

An arc flash is a sudden release of electrical energy due to an electric arc — a continuous, high-current discharge of...

Attosecond photonics sources refer to devices or systems that generate extremely short pulses of light on the order of...

One of the first lasers to find practical application. Generally, the pumping mechanism is an electric discharge, although...

1. The combination of the effects of two or more stimuli in any given sense to form a single sensation. With respect to...

A transistor designed to respond to either light or electrical signals.

A specific type of storage in which the material to be written on is heated above its transition temperature and switched in...

Gallium nitride (GaN) is a compound made up of gallium (Ga) and nitrogen (N). It is a wide-bandgap semiconductor material...

Broadening of a laser's spectral linewidth when the resonance frequencies of the atoms (or molecules) of the medium are not...

An excited energy state of an atom or atomic system that has a longer lifetime than the ordinary excited state and typically...

Optoelectronics is a branch of electronics that focuses on the study and application of devices and systems that use light...

An imaging system that uses a mosaic of tiny light-sensitive semiconductors (phototransistors) to produce individual outputs...

The principle that electronic energy transitions occur at such speeds that the nuclei of the atoms in the molecular system...

A laser in which the transition involved in stimulated emission of radiation takes place between two levels of an ionized...

An energy transition concerned with the combination of a photon and a phonon.

An electronic device consisting of a semiconductor material, generally germanium or silicon, and used for rectification,...

A spectroscopic technique in which an excitation band absorbs laser energy resulting in an electronic transition. The...

A type of change in the energy levels of molecules in a laser that results in lasing action. Vibronic transitions are those...

The displacement of spectrum lines, as determined by the increasing distance between, and the relative velocity of, the...

1. The range of frequencies or wavelengths over which radiations are absorbed or emitted in a transition between a specific...

Instruments used for measuring angles and occasionally lengths on the ground. The principal surveying instruments are the...

The principle that a light ray extending from one point to another will, after any number of reflections and refractions,...

A solid-state device similar to an ordinary transistor except that incident light on the PN junctions regulates the response...

A pump-probe technique whereby a single wavelength source may be used in order to excite a given sample to determine...

A camera designed to form a continuous record of an expansive section of the horizon. The typical panoramic camera is...

A photodetector employing photoregeneration of carriers in the channel region of an FET structure to provide photodetection...

Indium phosphide (InP) is a compound semiconductor material composed of indium (In) and phosphorus (P). It belongs to the...

An LCD that has pixels with no internal drive transistors.

A wide-angle lens is a type of camera lens that has a shorter focal length than a standard or normal lens, allowing it to...

A broadband filter is an electronic or electromagnetic device designed to pass a range of frequencies or signals within a...

Extreme ultraviolet (EUV) refers to a specific range of electromagnetic radiation in the ultraviolet part of the spectrum....

Azadioxatriangulenium is a type of organic compound with a unique triangular molecular structure. It is often abbreviated as...

The radiation-free transition that takes place within an ion, in which inner-shell vacancies in neutral atoms are filled by...

The law given by the formula: that is, the frequency of radiation emitted or absorbed by a system when E2 and E1...

A type of liquid-crystal display in which each display element contains an active component, such as a thin-film transistor,...

A material often used in the construction of optical instruments because of its low coefficient of thermal expansion (0.9 x...

The ongoing expansion of the universe based on observations of the recession of distant galaxies from each other as...

A semiconductor is a type of material that has electrical conductivity between that of a conductor and an insulator. In...

A color center, in the context of materials science and condensed matter physics, refers to a specific type of...

Refers to the transistors in which the working current flows through only one type of semiconductor material, either P-type...

A copolymer of styrene and acrylic used in molded optical components; it has a high refractive index and a low coefficient...

Zone of laser operation in which the direct, reflected or scattered light exceeds the laser's MPE and (by ANSI standards)...

Anisotropy refers to the property of exhibiting different values or characteristics when measured in different directions....

In semiconductor physics, the term bandgap refers to the energy range in a material where no electronic states are allowed....

A nondestructive test, also referred to as LASAT, that uses a high-energy laser pulse that is targeted on an adhesively...

A three-terminal semiconductor having only one PN junction and a stable, open-circuit, negative-resistance property.

MTF analysis/measurement equipment refers to instruments and tools used to measure and analyze the modulation transfer...

An atomic absorption spectrometer (AAS) is an analytical instrument used to determine the concentration of specific chemical...

The amount of energy required to raise the energy level of an atom; a necessity if the atom is to radiate energy. High...

An individual circuit component, complete in itself, such as a resistor, diode, capacitor or transistor. It is used as an...

An acronym of gamma ray amplification by stimulated emission of radiation. It is a gamma ray laser that operates between...

Calculations of lens aberrations whereby the first two terms of the series expansion are the only ones employed....

An optical material used in place of crown glass to produce lenses with extraordinary correction of chromatic aberrations....

The naturally occurring crystalline form of silicon dioxide. It is slightly birefringent and exhibits rotary dispersion of...

A frequency comb is a precise and regular series of equally spaced spectral lines, or frequencies, that are generated with...

A sudden, brief increase in current or voltage in a circuit that can damage sensitive components and instruments. Preventive...

The formation of transistors, diodes, capacitors, resistors and other electronic elements directly on a flake of silicon by...

Activity of a radionuclide having one spontaneous nuclear transition per second.

An OLED display that has an integrated electronic backplane as its substrate. Active-matrix OLED displays use at least two...

A transition boundary between two regions having different properties in a P-type semiconducting material.

Van der Waals forces refer to the attractive or repulsive forces between molecules (or parts of molecules) that arise from...

A form of shearing interferometer that contains a simple wedged (plane-parallel) glass plate with a nonzero optical path...

Fused quartz and silica are closely related materials, both composed primarily of silicon dioxide (SiO2), but they are...

The green line, in the spectrum of the aurora borealis, that has a wavelength of 5577 Å; it is caused by a forbidden...

A spatial light modulator consisting of a metallized polymer film stretched over an array of metal-oxide semiconductor...

The study concerned with the stimulation of chemical activity by laser light as a result of the absorption of photons by a...

Calorimetry is a branch of science that involves the measurement of heat flow in physical or chemical processes. It...

The spontaneous emittance of electromagnetic radiation by the nucleus of certain radioactive elements during their quantum...

A numerical representation of the rate at which a material will exhibit dimensional changes as a direct result of changes in...

The dip or gap in the profile of a laser beam's line width when it is both homogeneously and inhomogeneously broadened. When...

Thermal interface materials (TIMs) are substances or compounds used to enhance the thermal conductivity between two surfaces...

A long-pass filter is an optical filter that allows longer wavelengths of light to pass through while blocking or...

Periodic interruptions of a light beam incident on an absorbing medium that produce heat, expansion and acoustic wave...

A tachometer consisting of a light source, rotating perforated wheel and phototransistor to measure the rates of rotation of...

The probability that an atom in one state will move spontaneously to a lower state within a given unit of time.

The process by which an atomic system changes from one energy level to another by either the emission or absorption of...

A GRIN (gradient index) lens is a type of optical lens that utilizes a gradient in refractive index across its volume rather...

An absorption peak refers to a sharp increase or spike in the absorption of electromagnetic radiation at a particular...

Refers to transistors in which the working current flows through two types of semiconductor material: N- and P-type. In...

The resulting contraction or expansion of a piezoelectric crystal along an electric axis when the crystal is under the...

An OLED display that has an integrated electronic backplane as its substrate. Active-matrix OLED displays use at least two...

The time domain is a concept used in signal processing and analysis to describe signals in terms of their behavior over...

A transistor that uses an electro-luminescent source, a transparent base and a photoelectric collector.

The conductivity increase exhibited by some nonmetallic materials, resulting from the free carriers generated when photon...

A metal, alloy or compound that loses its electrical resistance at temperatures below a certain transition temperature...

The re-emission of absorbed energy, having the same wavelength as the incident energy, in an arbitrary direction from a...

Graphene is a two-dimensional allotrope of carbon consisting of a single layer of carbon atoms arranged in a hexagonal...

The laser output refers to the generated and emitted light produced by a laser system. This output is characterized by...

1. A compound lens consisting of two elements. If there is an air space between the elements it is called an...

A standard for fiber optic data transmission systems being developed by the American National Standards Institute (ANSI) and...

Westinghouse trade name for an alloy of iron, nickel and cobalt, which has the same thermal expansion as glass and therefore...

An atomic clock is a highly precise timekeeping device that uses the vibrations or oscillations of atoms as a reference for...

The term quantum refers to the fundamental unit or discrete amount of a physical quantity involved in interactions at the...

A vibrational transition refers to a change in the vibrational energy of a molecule. Molecules consist of atoms that are...

An optical instrument containing a gimballed sighting telescope, used to measure angular relationships in horizontal and...

A source of energy that produces needed excitation for population inversion in laser operation. The excitation source that...

When applied to LCD grids, the active matrix is a means of supplying power to pixels by use of a transistor and capacitor....

A device used to detect radiant energy by means of the thermal expansion of gas.

Schott Glass Technologies' trade name for a glass-ceramic material with a very low coefficient of thermal expansion.

Photoluminescence is a phenomenon in which a material absorbs photons (light) at one wavelength and then re-emits photons at...

The elimination of magnetic fields from within a material as that material makes the transition from the normal to...

That radiation emitted by an atom or molecule that has the same frequency as that of an incident particle; e.g., a photon....

A surface-mount device (SMD) is an electronic component that is mounted directly onto the surface of a printed circuit board...

A group of related lines that represent transitions between two spectroscopic terms, each of which may be complex. Also in...

An optical clock is a highly precise and advanced timekeeping device that relies on the oscillations of electromagnetic...

Optoacoustic, or photoacoustic, refers to a phenomenon and related techniques that involve the generation of acoustic waves...

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

A device that detects radiation by utilizing the influence of light in forming an electrical signal. It may be a phototube;...

Optical fiber optic switches are devices used in optical fiber communication systems to selectively route optical signals...

Also known as electronic photometer. A photometer with a photocell, phototransistor or phototube for measuring the intensity...