Photonics Dictionary

A calorimetric calculation from which the temperature vs. time dependence of any point on a sample can be determined, provided surface and bulk absorption, thermal conductivity and heat transfer...

A type of cooling system in which one fluid is used to carry heat off another without direct contact between the two.

A lamp designed to emit a large amount of infrared radiation; used in applications requiring heat.

A series of flanges or other conducting surfaces, usually metal, attached to an electronic device to transmit and dissipate heat that might damage internal circuitry.

The process of subjecting glass to temperature cycling to produce physico-chemical reactions that alter its properties. Similar processes can be accomplished with a laser -- most commonly a CO2,...

In reference to infrared, emissions that are like radio waves but that have a higher frequency.

A glass filter that transmits visible light while absorbing infrared energy (heat).

Glass that has been specially treated so that it will not shatter when exposed to high temperatures followed by immediate and rapid cooling.

A filter that allows heat radiation from an incident beam to pass without absorption or reflection.

A guided missile that uses an infrared sensor to detect and home in on an enemy target. The missile is guided by the high infrared emissions produced by a target, such as the heat from an aircraft or...

A device used in thin-film deposition; the material to be evaporated is placed in a crucible that is heated inductively by current passing through a coil around it.

A type of tubing used to protect optical fiber cables, consisting of a wire spiral of aluminum, galvanized steel or stainless steel, encased in a polyvinyl chloride or silicon rubber coating. These...

Infrared radiation emitted from a source that is not heated sufficiently to give off visible radiation.

A crucible made of electrically resistive material through which a current is passed to heat the material inside, which then evaporates and is deposited as a thin film on a substrate. Resistance...

Heating that results from the dissipation of energy.

The process of transferring collected energy from solar radiation into a heat-absorbing medium (e.g., an insulated tank of water) for use at a later time.

Ablation applied to polymers and chemical solids. Process of material removal that minimizes edge damage but will not heat the surrounding portion of the sample.

The measurement of heat energy as determined from absolute zero as the zero point on the scale. Increments are identical to the Celsius as well as Kelvin scales.

A thermoplastic or optically transmitting hard plastic produced by applying polymerization initiator and heat to a monomer.

Method for studying absorption coefficients of low-loss materials, in which a sample is allowed to come to thermal equilibrium with its surrounding blackened enclosure. The sample is irradiated with...

A process during which no heat enters or leaves the system.

Charged frozen pellets that are rapidly bombarded with a focused high-power laser to form a dense plasma that can be heated and sustained with neutral beams.

An operational mode for radiometers that analogs the method of operation of an angstrom pyrheliometer. In this mode, the rearward-facing cavity is electrically heated, while the forward cavity is...

The process of heating and slowly cooling a solid material, like glass or metal, to stabilize its thermal, electrical or optical properties or, as in semiconductor materials, to reverse lattice...

An oven or furnace that possesses the design requirements and heat control necessary to anneal glass for the optical industry.

An arc flash is a sudden release of electrical energy due to an electric arc — a continuous, high-current discharge of electricity between conductors or from a conductor to ground. Arc flashes...

The elimination of gases from the surfaces of a vacuum system by heating the surfaces when the pumping phase is occurring.

The application of reversible writing with a laser beam on particular storage materials. In one method, an amorphous film is heated and then crystallized for writing. Bubble writing involves the...

Heatless light emissions from living organisms caused by the combination of oxygen and pigments such as luciferin.

An ideal body that completely absorbs all radiant energy striking it and, therefore, appears perfectly black at all wavelengths. The radiation emitted by such a body when heated is referred to as...

A blackbody source, often simply referred to as a blackbody, is a theoretical or practical physical object that absorbs all electromagnetic radiation incident upon it and emits radiation in a...

A strong, heat-resistant glass that contains a minimum of 5 percent boric oxide.

A convex lens that brings an incident bundle of rays to a focus to produce intense heat at the focus.

A high-frequency pulse-rate laser with an output limited by the heat capacity of the laser medium. Instead of having continuous cooling, the laser operates until the medium reaches a maximum...

The production of visible light by infrared radiation whereby the light is produced by heat and not by any direct change in wavelength; the transformation is indirect.

An instrument used to measure the change of heat content of a system by measuring microwave power in terms of generated heat.

Calorimetry is a branch of science that involves the measurement of heat flow in physical or chemical processes. It encompasses various techniques and instruments used to quantify heat transfer,...

An electric discharge between two carbon rods that are touched together to start the arc and then separated slightly. The light comes from the heated carbon vapor. High-intensity arcs use cored...

Carbonization is a process in which organic materials are heated in the absence of air, leading to the decomposition of the material and the production of carbon-rich residue. During carbonization,...

A surface heat-treating process that produces a highly stressed surface. In case-hardening of glass, a plate of glass is heated almost to the softening point and then cooled quickly in a blast of...

1. The negative electrode of a device in an electrical circuit. 2. The positive electrode of a primary cell or storage battery. 3. The primary source of electrons in an electron tube, serving as the...