Photonics Dictionary

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 plano work, that property of a surface determining that it is convex and contacts a flat test glass at its center.

A null optic in the form of a concave spherical mirror; used for the test and evaluation of a hyperboloidal aspheric surface.

Homogeneous light refers to light that is uniform in intensity and color across a given area or space. In other words, homogeneous light sources produce illumination that is consistent and evenly...

An optical test table made up of two outer layers or "skins'' bonded to either side of a honeycomblike core, usually of aluminum or steel. It results in equal quality with greatly reduced weight...

Horizontal concentrations that comprise the dominant factor in atmospheric gradient correction. The range bias near due north and due south azimuths coincides with the systematic decrease in surface...

A glass rhomb that is used in photometry to compare two illuminated surfaces. This is accomplished by the rhomb's angles, which transmit two light beams, one from each of the two surfaces, so that...

Designed to observe objects below the surface of water. Not to be confused with hygroscopic.

Hyperspectral resolution refers to the level of detail or granularity in the spectral information captured by a hyperspectral imaging system. In hyperspectral imaging, the electromagnetic spectrum is...

Luminous flux incident per unit area of a surface; luminous incidence. (The use of the term "illumination" for this quantity conflicts with its more general meaning.)

Characteristic of a surface or object that has luminous flux incident upon it.

A desklike apparatus with an opal glass surface illuminated from beneath by fluorescent tubes. It is equipped with roll holders for aerial films and a low-power microscope or some form of...

Generally, the orientation of rays of light striking a surface.

A photometric instrument used to measure the illumination falling on a surface. It may be photoelectric or visual.

An electron tube that is used as a camera tube for a television system. When the picture to be transmitted is focused on a photosensitive surface, electrons are emitted from each section of the...

The distance from the last surface of a lens system to the image. For a thin lens system, this distance is equivalent to the distance from the rear nodal point of a lens to the image.

A semiconductor platelet laser that emits a coherent image by means of plane optical pumping over the platelet surface, and that uses laser threshold characteristics to produce a pronounced threshold...

An image intensifier, also known as an image intensification tube or image intensification device, is a specialized electronic device used to amplify low-light-level images to make them visible to...

Flux incident per unit area of a surface.

A ray of light that falls upon or strikes a surface of an object such as a lens. It is said to be incident to the surface.

Indirect time-of-flight (iTOF) is a method used in 3D imaging and depth sensing to measure the distance to an object based on the time delay between the emission of a light pulse and the detection of...

An infrared camera, also known as a thermal imaging camera or IR camera, is a device that captures and visualizes the infrared radiation emitted by objects, revealing temperature variations across...

An infrared detector is a device that is used to detect and measure infrared radiation, which lies beyond the visible spectrum of light. These detectors are utilized in various applications,...

A direct method of measuring refractive index that works best with flat-surfaced samples (i.e., those that are not dependent on special prism shapes) and produces data that are uniquely sensitive to...

Any object that emits radiation of a wavelength lying between about 0.75 to 1000 µm. A calibrated secondary source usually is a heated cavity (blackbody) or a filament lamp rated in wattage...

A vidicon that has a photoconductive surface that can be excited by infrared radiation.

An intensified charge-coupled device (ICCD) camera is an advanced imaging device that combines the capabilities of both an image intensifier and a charge-coupled device (CCD) sensor to achieve...

An interferometer is a scientific instrument that utilizes the principle of interference to measure differences in the path length, wavelength, phase, or amplitude of coherent electromagnetic waves....

Interferometric modulator display (IMOD) is a type of display technology used in electronic devices, known for its energy efficiency and ability to produce high-quality reflective color displays....

With reference to absorbance, absorptance, transmittance and the like, the processes occurring within a specimen between the entry and exit surfaces.

The ratio of the radiant power transmitted to the second surface of a medium to the corresponding radiant power that has just passed through the first surface. Internal transmittance does not denote...

An invisibility cloak is technology that would render an object or individual invisible to the observer. In scientific research, efforts to create real-life invisibility cloaks have been...

The ejecting of ions from the surface of a material.

Ion-beam sputtering (IBS) is a physical vapor deposition (PVD) technique used for depositing thin films onto substrates. It involves bombarding a target material with a beam of energetic ions,...

The gas of charged particles that begins approximately 50 km above the surface of the Earth and contains a sufficient quantity of electrons and ions to affect the propagation of radio waves.

The rainbow exhibition of colors, usually caused by interference of light of different wavelengths reflected from superficial layers in the surface of a material.

Radiant flux incident per unit area of a surface. Also called radiant flux density.

A curve or surface having equivalent light intensity.

Label-free refers to a technique or method that does not require the use of additional labels, tags, or markers to detect or identify specific components or entities. In various scientific and...

Flux per unit solid angle leaving a surface in any direction is proportional to the cosine of the angle between that direction and the normal to the surface. A material that obeys Lambert's cosine...

A method of depositing crystalline films one molecular layer at a time, by dipping the substrate into water containing a polymer that forms a single layer of molecular chains on the surface. This...

A metal tool used to grind lenses with loose abrasive (see diamond cutting tool). The functional surface of the lap is carefully formed to be opposite the curve to be produced on the glass (concave...

1. The process of wearing down the surface of a softer material by rubbing it under pressure against the surface of a harder material that has been formed in the shape opposite to that desired on the...

Lapping and polishing services involve specialized processes used to improve the surface finish and dimensional accuracy of components to meet specific requirements or standards. These services are...

Laser ablation is a process that involves the removal or erosion of material from a target surface using laser energy. This technique is widely used in various scientific, industrial, and medical...

Laser annealing is a process that involves using a laser beam to heat and modify the microstructure of a material, typically a thin film or surface layer, with the objective of improving its...

A natural or mechanical system adversely affected by the influence of laser radiation. During laser damage the common effect of the radiation on the surface of interest is heat accumulation due to...

High power laser ablation device that by pulsed operation produces holes of controllable dimension on the scale of microns. Laser drill applications include turbine manufacturing and surface metal...

Laser marking is a process in which a laser beam is used to mark or engrave a surface by altering its properties or appearance. This technique is widely used for labeling, identification, and...