Photonics Dictionary

An electron-gun system is an assembly used to generate and control a focused beam of electrons. Electron guns find applications in various fields, including cathode ray tubes (CRTs), electron...

An electrowetting display (EWD) is a type of electronic display technology that utilizes the principles of electrowetting to control the behavior of colored oil droplets on a hydrophobic surface....

Emission spectroscopy is a technique used to study the emission of electromagnetic radiation (light) by atoms, molecules, or ions when they undergo transitions from excited states to lower energy...

An endoscope is a medical device used for visualizing and examining the interior of hollow organs, body cavities, or confined spaces within the body. It consists of a flexible or rigid tube equipped...

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...

An erbium-doped fiber laser (EDFL) is a type of laser that uses an optical fiber doped with erbium ions (Er³+) as the gain medium. These lasers are widely used in telecommunications, medical...

An excimer laser is a type of ultraviolet laser that emits short pulses of light in the ultraviolet spectrum. The term excimer is derived from excited dimer, reflecting the nature of the gain medium...

The signal-to-noise ratio (SNR) obtained with a Fourier transform spectrometer when detector noise prevails, which exceeds the SNR of a scanning spectrometer in the same time by a factor proportional...

A fiber optic attenuator is a passive optical component designed to attenuate or decrease the intensity of an optical signal traveling through a fiber optic link. It achieves this by introducing a...

A fiber optic cable assembly refers to a complete unit consisting of optical fibers, connectors, protective jackets, and other components that are assembled together to facilitate the transmission of...

A fiber optic sensor is a device that uses optical fibers to detect and measure physical, chemical, biological, or environmental parameters. Unlike traditional electrical sensors, fiber optic sensors...

A fiber optic transceiver, often simply referred to as an "optical transceiver," is a device used in fiber optic communications to transmit and receive data over optical fibers. It integrates both a...

The field of view (FOV) refers to the extent of the observable world or the visible area that can be seen at any given moment through a device, such as an optical instrument, camera, or sensor. It is...

Flow chemistry, also known as continuous-flow chemistry, is a chemical manufacturing process where reactions take place in a continuous stream of fluids (liquids or gases) rather than in batch...

Flow cytometry is a powerful technique used in biology and medicine for the quantitative analysis of the physical and chemical characteristics of cells and particles suspended in a fluid. The method...

Fluorescence correlation spectroscopy (FCS) is a powerful analytical technique used to study the dynamics and interactions of fluorescently labeled molecules in solution at the single-molecule level....

Fluorescent proteins are proteins that exhibit the property of fluorescence, which is the ability to absorb light at a specific wavelength and emit light at a longer wavelength. These proteins are...

Fluoride fibers are optical fibers made from fluoride-based materials, typically fluoride glasses or crystalline fluoride compounds. These fibers are characterized by their unique optical properties,...

FMCW lidar stands for frequency-modulated continuous wave lidar. It is a type of lidar (light detection and ranging) technology used for remote sensing, distance measurement, and 3D mapping. FMCW...

One of the electrodes used to focus the electron beam of a cathode-ray tube. As the electrode's voltage is changed, its electrical field is changed, resulting in a change of the electron beam's spot...

Voltage that produces current flow in the direction of lesser resistance to the steady-state direct current, i.e., from the anode to the cathode.

A free-electron laser (FEL) is a type of laser that generates coherent, high-intensity electromagnetic radiation by using a beam of accelerated electrons as the lasing medium. Unlike traditional...

Free-space optics (FSO), also known as optical wireless communication or optical wireless networking, refers to the transmission of data using modulated beams of light through free space (air or a...

A Fresnel lens is a type of optical lens that consists of a series of concentric grooves or steps carved into a flat, thin piece of transparent material, typically plastic or glass. This design...

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 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...

A galvanometer is an instrument used for detecting and measuring small electric currents. It typically consists of a coil of wire suspended in a magnetic field, with a pointer attached to the coil....

GaN (gallium nitride) distributed feedback (DFB) lasers refer to a specific type of semiconductor laser based on Gallium Nitride materials and designed with a distributed feedback structure. These...

Germanium crystal refers to a crystalline form of the element germanium (Ge), which is a metalloid and semiconductor commonly used in various electronic and optical applications. Germanium crystals...

The term gradient-index profile refers to a specific type of refractive index distribution within an optical material. In optics, the refractive index of a material describes how much the speed of...

A GRIN (gradient index) lens is a type of optical lens that utilizes a gradient in refractive index across its volume rather than having a uniform refractive index like conventional lenses. This...

A helium-neon (HeNe) laser is a type of gas laser that emits visible red light at a wavelength of 632.8 nm. It operates based on the principle of stimulated emission of photons from excited helium...

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...

Holmium lasers are a type of medical laser that utilizes holmium-doped crystals as the gain medium. The term holmium laser is often associated with a specific type of laser used in urology for...

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...

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 camera that uses an image converter tube in such a way that voltage waveforms applied to internal electrodes cause the original image to be switched on and off very rapidly, thus offering time...

A modified form of an image-retaining panel that can be used in subdued daylight. This is achieved by adding a layer of zinc oxide between the panel's phosphor layer and its rear electrode. The zinc...

Immunohistochemistry (IHC) is a method for detecting antigens or haptens in cells of a tissue section by using labeled antibodies to bind specifically to their antigens. IHC is used for disease...

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...

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...

Inductance is a fundamental property of an electrical circuit or component that describes its ability to store energy in a magnetic field when an electric current flows through it. It is typically...

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 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...

Injection locking, also known as injection-phase locking or injection-phase control, is a phenomenon in which a weak signal is synchronized with a stronger signal due to the injection of energy or...

Injection molding is a manufacturing process used to produce parts by injecting molten material into a mold. It is widely used for creating a variety of plastic products, but it can also be used with...

In a camera, the movement of one or more lenses behind the front lens, rather than of the front lens itself, to bring the subject into focus. Because internal focusing does not require the front lens...