Photonics Dictionary

Harmonic generation refers to a nonlinear optical process in which incoming photons interact with a material and produce new photons at integer multiples of the frequency of the incoming photons....

The heat-affected zone (HAZ) refers to the portion of a material, typically metal, that experiences changes in its microstructure and mechanical properties due to the heat generated during welding,...

A heat sink for a laser is a device designed to absorb and dissipate the excess heat generated by the laser during operation. This is crucial to maintain the laser's performance, prevent overheating,...

A material used in photodynamic therapy that is retained selectively by tumor tissue when injected into the body; it then fluoresces when exposed to blue light and necroses when exposed to red laser...

The total fusion and sealing of materials, or usually an enclosure, to ensure that they are airtight.

A heterojunction is a junction formed between two different semiconductor materials with differing band gaps. These materials can be of the same or different types (e.g., both n-type, both p-type, or...

A method used in integrated optics; formed by growing an epitaxial layer of active material, removing it from its base and splicing it onto a passive substrate.

Extensive data storage in the form of bits, with the use of high-resolution photographic materials and optics, and generally a laser.

A high-speed motion camera, also known as a high-speed camera or slow-motion camera, is a specialized imaging device designed to capture fast-moving events or phenomena at extremely high frame rates....

An imaging device whose technology contributes three specific advantages: ability to study large solid specimens that exhibit behavior in bulk; conduction of in situ studies of radiation damage; and...

A holographic camera, also known as a holographic imaging system or holographic recorder, is a specialized device used to capture 3D holographic images of objects or scenes. Unlike conventional...

A holographic grating is a type of diffraction grating that is produced using holographic recording techniques. It consists of a periodic structure of alternating transparent and opaque regions,...

Holographic tomography is an advanced imaging technique that combines holography and tomography to provide three-dimensional reconstructions of transparent or weakly scattering objects with high...

Device in which the various circuit elements are fabricated in different substrate materials and then appropriately joined together so that the various substrate materials can be chosen to optimize...

A hydrogel is a three-dimensional network of polymer chains that are hydrophilic, meaning they have a strong affinity for water. This network structure allows hydrogels to absorb and retain large...

A photoreceptor material used in solar cells and in drums for laser printers and high-speed copiers because of its high quantum efficiency over a wide spectral band, high data-rate capability and...

Hydrophilic is a term used to describe substances or materials that have an affinity for water. The word hydrophilic comes from the Greek words "hydro," meaning water, and "philos," meaning loving or...

Hydrophobic is a term used to describe substances or materials that repel or do not readily interact with water. The word hydrophobic comes from the Greek words "hydro," meaning water, and "phobos,"...

In fiber optics, a material whose properties, usually of transmission, are distinctly affected by the absorption of water vapor.

E.I. duPont's trade name for a material used in the jacket of fiber optic cables. It is flame-retardant, thermally stable and resistant to oxidation, ozone and radiation.

Hyperspectral imaging is an advanced imaging technique that captures and processes information from across the electromagnetic spectrum. Unlike traditional imaging systems that record only a few...

A hyperspectral imaging camera is a sophisticated imaging device capable of capturing and processing data across a wide range of wavelengths within the electromagnetic spectrum, typically from...

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...

Pertaining to the possession of photoelectric characteristics as a result of the properties of the true crystal and not of foreign materials.

In semiconductor physics and materials science, the term "III-V materials" refers to compounds composed of elements from group III and group V of the periodic table. More specifically, these...

A camera tube similar in design to the iconoscope. However, the image formed in the image iconoscope is projected on a photocathode that emits photoelectrons to be focused on a material, forming the...

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...

A thermoplastic or thermosetting material used to hold an object fixed and keep it from deterioration. In microcircuitry, the process of imbedding is known as potting.

A radiation detector with its active medium mounted within a lens that focuses the radiation signal. The improvement in detector performance is a function of the indices of refraction of the lens...

In the context of optical materials, the term "impurity level" refers to the presence of foreign atoms or molecules within the material that deviate from its regular or intrinsic composition. These...

The presence, within the body of the glass, of extraneous or alien material. See seed; striae.

A bundle of filaments of optical glass or other transparent materials that transmit only light, not optical images. The arrangement of the individual fibers in the bundle is not sufficiently regular...

The ratio of the velocity of light in a vacuum to the velocity of light in a refractive material for a given wavelength.

A material, often a liquid or cement, whose refractive index is nearly equal to the fiber's core index, used to reduce Fresnel reflection from a fiber end face.

A semiconductor material that is used as an infrared detector for light up to 5 µm in wavelength.

An InGaAs (indium gallium arsenide) camera is a type of imaging device that utilizes InGaAs sensors to capture images in the near-infrared (NIR) spectrum. InGaAs is a semiconductor material that is...

Indium phosphide (InP) is a compound semiconductor material composed of indium (In) and phosphorus (P). It belongs to the III-V group of semiconductors, where elements from groups III and V of the...

A material widely used as a transparent conductive coating.

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.

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,...

An infrared lens is an optical component specifically designed and optimized for transmitting, focusing, or manipulating infrared (IR) radiation within the infrared spectrum. These lenses are used in...

An infrared light-emitting diode (IR LED) is a semiconductor device that emits infrared light when an electric current passes through it. Similar to standard LEDs that emit visible light, IR LEDs are...

Infrared optics refer to optical components and systems designed to manipulate and control infrared (IR) light, which lies beyond the visible spectrum. These components are crucial for various...

The range of materials that, unlike glass, may be used in the infrared. Water-soluble salts, such as cesium iodide, and other substances such as arsenic sulfide, selenium, thallium bromide-iodide and...

An optical component coated to reflect infrared radiation. Gold, silver and aluminum are typical coating materials.

A spectrophotometer having a prism or, more frequently, a grating for the study and recording of infrared spectra. It usually consists of a radiation source such as a Nernst glower, a monochromator,...

1. A thin parallel plate of material that transmits in the infrared region. See infrared optical material. 2. A spectral region (of the infrared) in which the atmosphere transmits.

An InGaAs photodiode refers to a photodetector device that is constructed using a semiconductor material composed of a combination of indium (In), gallium (Ga), and arsenic (As). The term InGaAs...