Photonics Dictionary

An Abbe refractometer is a scientific instrument used to measure the refractive index of liquids and solids. Named after the German physicist Ernst Abbe, this device operates on the principle of...

Ablative photodecomposition refers to a process where a material is broken down or decomposed due to exposure to intense light, typically laser light. In this process, the photons from the laser...

An absorption band is a range of wavelengths, frequencies, or energies in the electromagnetic spectrum within which a substance absorbs radiation. It appears as a dark band in a spectrum where the...

An absorption line is a dark line in a spectrum that occurs when a specific wavelength of light is absorbed by atoms or molecules in a medium (such as a gas or a solid) as light passes through it....

An absorption peak refers to a sharp increase or spike in the absorption of electromagnetic radiation at a particular wavelength or energy level. It is a distinctive feature in the absorption...

An absorption spectrum is a graphical representation of the absorption of light by a material as a function of wavelength, frequency, or energy. It displays the specific wavelengths of light that are...

Acrylic refers to a type of synthetic polymer material known for its versatility, clarity, and durability. It is commonly used in a wide range of applications due to its beneficial properties. Here...

Actinic glass is a type of glass specifically designed to filter or block ultraviolet (UV) light and other forms of actinic radiation. UV filtering: Actinic glass effectively absorbs or...

In various fields of science and technology, an active element typically refers to a component or substance that actively participates in or facilitates a process, operation, or reaction. Here are...

In the context of a laser diode, the active region is a critical part of the device where the primary light generation occurs. Laser diode active region: The active region in a laser diode is...

Additive manufacturing (AM), also known as 3D printing, is a manufacturing process that involves creating three-dimensional objects by adding material layer by layer. This is in contrast to...

The all-encompassing noise associated with a given environment, usually being a composite of a number of sources, far and near.

The angular spectrum approach is a mathematical and computational technique used in the field of optics to analyze and simulate the propagation of optical waves, particularly in the context of wave...

Anisotropic is a term used to describe a material or substance that exhibits different properties or behaviors in different directions. In other words, the physical or mechanical characteristics of...

Anisotropy refers to the property of exhibiting different values or characteristics when measured in different directions. In various fields, including physics, materials science, and geology,...

A spectral phenomenon in which the degree of the photoresponse of an illuminated semiconductor is determined by the wavelength composition of the incident light.

Attenuated total reflectance (ATR) spectroscopy is a technique used in analytical chemistry to obtain IR spectra of samples. It is particularly useful for analyzing solid and liquid samples without...

Autofluorescence refers to the natural emission of fluorescence exhibited by certain biological structures or molecules when exposed to light. Unlike fluorescence that results from the application of...

Backscatter refers to the phenomenon in which radiation or waves are scattered backward, opposite to the direction of the incident beam. This occurs when the incident radiation encounters a target or...

The term used in reference to vacuum systems using oil and diffusion pumps, describes the migration of pump fluids and their decomposition products into the vacuum chamber.

A boson is a type of fundamental particle that follows Bose-Einstein statistics, which dictate the statistical distribution of identical particles with integer spin. Bosons are one of the two main...

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,...

Chemical vapor deposition (CVD) equipment refers to a class of specialized apparatus used in the process of chemical vapor deposition, a technique for depositing thin films of various materials onto...

1. Attribute of a visual sensation that permits a judgment to be made of the amount of pure chromatic color present. 2. The portion of a composite video signal that carries the chrominance values,...

A filter that passes a series of wavelength regions that are at equal distances from one another, such that its output resembles the teeth of a comb. In video transmission, a comb filter is used to...

A filter used in photography to change the spectral composition of light entering a camera, or to adjust color balance during printing.

A type of video signal in which the luminance and chrominance portions of the signal, or the luma and chroma, have been combined according to standards such as NTSC, PAL or SECAM.

A transducer composed of more than one high-pass, bandpass, low-pass or band-elimination filter.

Glass of special composition that is melted, formed into desired shapes, and subjected to a high-temperature treatment in which the glass undergoes a stage of nucleic formation, and a second stage,...

A dichroic coating, also known as a dichroic filter or dichroic mirror, is an optical coating designed to selectively transmit or reflect certain wavelengths of light while simultaneously absorbing...

Diffuse reflectance spectroscopy (DRS) is a nondestructive analytical technique used to investigate the optical properties of materials, particularly in the field of spectroscopy. Unlike traditional...

A composite derived from aluminum alloy powder and silicon carbide, used as an optical substrate in air- and spacecraft applications. It is as light as aluminum but exhibits greater strength and...

An emission spectrum is a graphical representation or a characteristic pattern of the wavelengths or frequencies of light emitted by a source, such as an atom, molecule, or celestial object. It shows...

Enantiomers are a pair of molecules that are non-superimposable mirror images of each other, similar to left and right hands. They are stereoisomers, meaning they have the same molecular formula and...

Epitaxial deposition is a process used in semiconductor manufacturing and materials science to grow a thin crystalline layer, known as an epitaxial layer, on a substrate. The term epitaxial refers to...

Epitaxial equipment refers to a set of specialized tools and systems used in the process of epitaxy, which is the growth of crystalline layers on a substrate material. Epitaxial growth is a critical...

A fiber optic preform is a cylindrical glass rod or tube used as the starting material for manufacturing optical fibers. It serves as the precursor from which optical fibers are drawn. The process of...

A fiber optic spectrometer is a device used for measuring the spectral content of light. It utilizes optical fibers to transmit light from a source to a spectrometer unit, where the light is...

The focal length of a lens is the distance between the lens's optical center (or principal point) and the image sensor or film when the lens is focused at infinity. In simple terms, it is the...

In communcations and video signals, the portion of a composite signal between the leading edge of the horizontal blanking pulse and the leading edge of the horizontal synchronization pulse.

FTIR (Fourier transform infrared) spectrometer is a powerful analytical instrument used to obtain an infrared spectrum of absorption or emission of a solid, liquid, or gas sample. It operates based...

A GaAlAs laser is a type of semiconductor laser diode that emits light in the near-infrared region of the electromagnetic spectrum. It is composed of layers of gallium, aluminum, and arsenic, hence...

Gallium arsenide phosphide (GaAsP) is a semiconductor alloy composed of gallium (Ga), arsenic (As), and phosphorus (P). It is commonly used in the fabrication of optoelectronic devices, particularly...

Gallium nitride (GaN) is a compound made up of gallium (Ga) and nitrogen (N). It is a wide-bandgap semiconductor material that exhibits unique electrical and optical properties. Gallium nitride is...