Photonics Dictionary

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...

A fiber-coupled LED (light-emitting diode) refers to an LED device that is optically coupled to an optical fiber for the purpose of efficient light transmission. In this configuration, the LED serves...

A fiber-coupled photoconductive antenna (FCPA) is a type of optoelectronic device that combines a photoconductive antenna with optical fibers for the purpose of generating or detecting terahertz...

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...

A Fizeau interferometer is an interferometric device that uses the principle of interference to measure the surface flatness and quality of optical components. It consists of a light source,...

A flexible display refers to a type of electronic visual display that is designed to be bendable, foldable, or rollable, allowing for unconventional form factors and enhanced portability. Unlike...

The Floquet Fermi liquid state refers to a concept in condensed matter physics that arises when a system is subjected to periodic driving or modulation, typically by an external periodic field such...

A flowmeter is a device used to measure the flow rate or quantity of a fluid passing through a particular point in a system. It works by sensing the velocity of the fluid passing through it and...

Fluorescence is a type of luminescence, which is the emission of light by a substance that has absorbed light or other electromagnetic radiation. Specifically, fluorescence involves the absorption of...

Fluorescence and phosphorescence spectroscopy are techniques used to study the emission of light (photons) by molecules following their excitation by external energy sources. While both processes...

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....

Fluorescence lifetime imaging (FLIM) is an advanced imaging technique that provides information about the lifetime of fluorescence emissions from fluorophores within a sample. Unlike traditional...

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...

A fluorescent screen refers to a phosphorescent or fluorescent-coated surface that emits visible light when exposed to other forms of electromagnetic radiation, such as x-rays or ultraviolet light....

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,...

A fluorophore is a molecule or a portion of a molecule that has the ability to emit light upon excitation by an external energy source, such as ultraviolet or visible light. The process by which a...

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...

Förster resonance energy transfer (FRET) is a mechanism describing the transfer of energy between two closely spaced fluorescent molecules. This phenomenon is named after the German scientist...

A frame grabber is a hardware device or interface card that connects to a computer or imaging system and is designed to capture and digitize frames of video or images from a video source such as a...

Frame rate refers to the frequency at which consecutive images, or frames, are displayed in a video sequence. It is typically measured in frames per second (fps) and determines the smoothness and...

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...

Freeform mirrors refer to reflective optical components that deviate from traditional symmetric or rotationally symmetric shapes, such as spheres or paraboloids. Unlike conventional mirrors, which...

Freeform optics refers to the design and fabrication of optical surfaces that do not follow traditional symmetric shapes, such as spheres or aspheres. Unlike standard optical components with...

A frequency comb is a precise and regular series of equally spaced spectral lines, or frequencies, that are generated with great accuracy. The term "frequency comb" is often associated with the Nobel...

The frequency domain is a concept used in signal processing and analysis to represent signals and data in terms of their frequency components. In contrast to the time domain, where signals are...

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...

Functional materials refer to materials that possess specific properties or functionalities that make them suitable for particular applications or purposes. These materials are designed and...

Functional near-infrared spectroscopy (fNIRS) is a non-invasive neuroimaging technique that measures changes in hemoglobin concentration in the brain. It utilizes near-infrared light to penetrate the...

Fused quartz and silica are closely related materials, both composed primarily of silicon dioxide (SiO2), but they are produced through different manufacturing processes and have distinct properties...

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...

Gain-switching is a technique used in lasers to generate short pulses of light by modulating the gain of the laser medium. This method is distinct from Q-switching and mode-locking, two other common...

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 arsenide (GaAs) is a compound semiconductor material composed of gallium (Ga) and arsenic (As). It belongs to the III-V group of semiconductors and has a zincblende crystal structure. GaAs 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....

A galvanometric scanner, also known as a galvanometer scanner or galvo scanner, is a type of optical scanning device used to rapidly and precisely direct a laser beam or other light source to...

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...

Gallium nitride-based light-emitting diodes (GaN-based LEDs) are semiconductor devices that emit light when an electric current passes through them. These LEDs are constructed using gallium nitride...

One of the first lasers to find practical application. Generally, the pumping mechanism is an electric discharge, although some high-power forms employ chemical reaction or gas compression and...

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...

Germicidal ultraviolet (GUV) refers to a specific range of UV radiation that has disinfectant properties capable of killing or inactivating microorganisms, including bacteria, viruses, and fungi. The...

GigE, short for gigabit Ethernet, refers to a standard for high-speed Ethernet communication, capable of transmitting data at rates of up to 1 gigabit per second (Gbps), or 1000 megabits per second...

Gold colloid aggregates refer to clusters or assemblies of gold nanoparticles suspended in a liquid medium. These aggregates are formed when individual gold nanoparticles come together due to various...

A grating beamsplitter is an optical device that utilizes the principles of diffraction to split a beam of light into multiple beams, often redirecting them at specific angles. It is based on the...

A specific, right-angle prism having a transmission grating replicated on its hypotenuse face and used in applications requiring a system that can produce in-line viewing for one wavelength.

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 gyroscope is a mechanical device consisting of a spinning disk or wheel mounted on a spinning axis in such a way that its orientation remains fixed regardless of any movement of its mounting...