Photonics Dictionary

A 2D profile sensor is a type of sensor used in various industrial and technological applications to measure and capture detailed information about the shape, contour, or profile of an object in two...

An abridged spectrophotometer refers to a simplified or compact version of a traditional spectrophotometer, which is a scientific instrument used to measure the intensity of light at different...

Absorption is the process by which a material takes in energy from electromagnetic radiation (such as light, heat, or sound) and converts it to other forms of energy, typically internal energy (such...

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...

Absorption spectroscopy is a fundamental analytical technique used to study the interaction between electromagnetic radiation and matter. It involves measuring the absorption of light by a sample...

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...

An accelerometer is a sensor or transducer that measures the rate of change of velocity of an object, or in simpler terms, it measures acceleration. Accelerometers are widely used in various...

In various scientific fields, the term acceptor has distinct meanings: Chemistry: An acceptor is an atom, ion, or molecule that receives electrons during a chemical reaction. In the context of...

Accessible radiation refers to the portion of radiation from a source that can be reached or detected by humans, instruments, or devices under specific conditions of use. This term is often used in...

An acousto-optic tunable filter (AOTF) is a device that utilizes the acousto-optic effect to selectively filter and transmit light based on its wavelength or frequency. It operates by applying an...

An acquisition control processor typically refers to a specialized computer or electronic system component used in industrial automation, data acquisition systems, or scientific instrumentation. Its...

The actinides are a series of 15 chemical elements in the periodic table, with atomic numbers from 89 to 103. They are named after actinium, the first element in the series. Elements: The...

Actinochemistry refers to the branch of chemistry that studies the chemical effects of radiation, particularly light, on substances and chemical reactions. Here are the key aspects of...

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...

An active infrared (IR) system is a type of technology that uses infrared radiation actively emitted and detected by sensors for various purposes. Here are the key features and applications of active...

In the context of semiconductors and electronics, the active layer is the part of a semiconductor device where the essential electronic activities take place. This includes the movement and...

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...

An active-matrix display is a type of flat-panel display technology where each pixel is actively controlled by one or more thin-film transistors (TFTs). This technology is commonly used in liquid...

An OLED display that has an integrated electronic backplane as its substrate. Active-matrix OLED displays use at least two thin-film transistors (TFTs) to control the on-current at each OLED cell or...

Radioactivity refers to the spontaneous emission of radiation from the nucleus of an unstable atom. This emission occurs as the nucleus undergoes radioactive decay, which is a natural and random...

An actuator is a mechanical or electromechanical device that is responsible for moving or controlling a mechanism or system. It converts various forms of energy (such as electrical, hydraulic,...

Additive color mixing refers to the process of creating colors by combining different wavelengths of light. In this system, red, green, and blue (RGB) are considered primary colors. By mixing varying...

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 use of optical or electronic recording systems to extract information from the terrain, while aloft, for reconnaissance applications.

The creation of a planned sequence of data input that is obtained while airborne for use in aerial photogrammetry and other types of map making and surveying. The data can be photographic, electronic...

Alternating current (AC) is an electrical current in which the direction of flow of electric charge periodically reverses. This reversal occurs at regular intervals, typically in a sinusoidal...

A device that enlarges and strengthens a signal's output without significantly distorting its original waveshape. There are amplifiers for acoustical, optical and electronic signals.

Gamma ray radiation released when matter and antimatter, such as electron and positron, unite and eliminate each other, transforming completely into energy. The resulting gamma ray spectrum depends...

The part of an electrical circuit in which the electrons leave (a cathode-ray tube) or enter (an electrolytic cell) a unit in the circuit.

A device that prevents electrons from a saturated pixel in a CCD imaging device from spilling into an adjacent pixel. The antiblooming gate drains a pixel of any charge in excess of its full-well...

An APD detector, or avalanche photodiode detector, is a type of photodetector used to detect light or optical signals by converting incoming photons into electrical current. It operates based on the...

A loss of resolution or detail in a television signal caused by the size of the electron scanning beam.

Area scan, in the context of imaging and cameras, refers to a method of capturing an entire two-dimensional image in a single snapshot or exposure. Unlike line scan, which captures images one line at...

An argon-fluoride (ArF) excimer laser is a type of ultraviolet laser that operates using a mixture of argon and fluorine gases. Excimer lasers are a class of gas lasers that emit light in the UV...

gas laser using ionized argon as the active medium and applying electronic excitation in order to produce the laser light

The efficiency of scattering by an atom in a particular direction, expressed as: where AA is the amplitude of the wave from the atom and AE is the amplitude of the wave from a free electron.

Attenuation refers to the gradual loss or reduction of intensity, force, or magnitude of a particular property as it propagates through a medium or travels over a distance. This concept is prevalent...

An attenuator is an electronic or optical device used to reduce the power or intensity of a signal without significantly affecting its waveform or other characteristics. Attenuators are commonly used...

An attoampere (aA) is a unit of electric current in the International System of Units (SI). It is equal to one quintillionth (10-18) of an ampere. The ampere, symbolized as "A," is the base unit of...

Attosecond photonics sources refer to devices or systems that generate extremely short pulses of light on the order of attoseconds (1 attosecond = 10-18 seconds). These ultrafast light pulses are in...

Attosecond-pump attosecond-probe spectroscopy (APAP) is an advanced technique in ultrafast spectroscopy that allows scientists to study the dynamics of electronic processes occurring on extremely...

The radiation-free transition that takes place within an ion, in which inner-shell vacancies in neutral atoms are filled by outer-shell electrons, thereby transferring energy to other electrons,...

The energy analysis of electrons released in a secondary step following initial excitation or ionization.