Photonics Dictionary

A technique used in integrated optics where a groove is cut on a substrate surface and covered by a thin film to facilitate the construction of filters, resonators, beamsplitters and grating couplers...

A custom optic refers to an optical component that is designed, manufactured, and tailored to meet specific requirements or applications. These optics can include lenses, mirrors, prisms, filters, or...

The distance, on either side of the object plane focused on, through which satisfactory image definition can be obtained. For the special case of an imaging system with lens axis perpindicular to the...

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...

Differential interference contrast (DIC) microscopy, also known as Nomarski interference contrast microscopy, is an optical imaging technique used in microscopy to enhance the contrast of transparent...

A diffraction grating is an optical component consisting of a surface with a periodic structure of equally spaced, parallel grooves or rulings. These rulings act as an array of closely spaced slits...

A diode laser is a type of laser that uses a semiconductor diode as the active medium to generate coherent light. Semiconductor diodes are electronic devices that conduct electricity primarily in one...

A diverging lens is a type of lens that causes parallel rays of light to spread out or diverge. It is thinner in the center than at the edges and is commonly referred to as a concave lens. The most...

A device used to detect and measure the quantity of exposure to nuclear or x-ray radiation, and dependent on the fact that such radiation ionizes a gas.

An electro-optic modulator (EOM) is a device used to modulate the amplitude, phase, or polarization of light waves using an external electrical signal. Electro-optic modulation is a fundamental...

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....

An enzyme-linked immunosorbent assay (ELISA) is a laboratory technique used to detect and measure the presence of specific substances, such as antibodies, antigens, proteins, hormones, or other...

An etalon is an optical device that consists of two parallel reflecting surfaces separated by a precise and known distance. It operates based on the principle of optical interference and is used to...

An exciton is a quasiparticle that represents the bound state of an electron and a hole in a solid-state material, typically a semiconductor or an insulator. In simpler terms, an exciton is a paired...

An f-theta lens, also known as an f-theta scan lens or simply an f-theta lens system, is a specialized optical component used in laser scanning systems, particularly in laser marking, engraving, and...

A multiple-beam interferometer, usually consisting of two flat plates, with high reflective ability. The plates are set parallel to one another by spacers so that lightwaves may bounce back and forth...

A means of determining a prism's index of refraction by placing the prism so that its emergent face is perpendicular to the incident beam. This arrangement permits the determination of the prism's...

1. One of the plane-reflecting surfaces on a multisurfaced polygon. 2. The cleaved end mirror of a laser diode's active region.

Fiber joints, also known as fiber optic splices, refer to the connection points where two optical fibers are permanently joined together to form a continuous optical transmission path. These joints...

A fiber laser is a type of laser in which the active gain medium is an optical fiber doped with rare-earth ions such as erbium, ytterbium, or neodymium. Fiber lasers generate coherent light through...

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 device used to prepare optical fiber end faces; a scribe line made by the cleaver's blade propagates across the fiber, resulting in a clean break.

A fiber optic gyroscope (FOG) is a type of gyroscope that uses the interference of light waves to detect changes in orientation or rotation. It operates based on the principle of the Sagnac effect,...

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 distance between the surface of a ferrule and the surface of a fiber end, provided that the ferrule extends above the fiber end. If the fiber end extends above the ferrule surface, the difference...

Filoviruses are a family of viruses that are responsible for severe and often fatal hemorrhagic fevers in humans and non-human primates. The name "filovirus" is derived from their filamentous...

For a Fabry-Perot interferometer or etalon, a value for the transmission bandwidth which can be calculated as the ratio of the free spectral range to the full width half maximum of the transmission...

Fizeau fringes are interference fringes observed in an interferometer, specifically in a Fizeau interferometer. The Fizeau interferometer is named after the French physicist Armand Fizeau, who...

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...

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...

Fluence is a term used in various scientific and technical disciplines to describe the amount of something per unit area. The specific meaning of fluence can vary depending on the context in which it...

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...

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...

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...

The process whereby a rotating wheel carries grains of an abrasive, suspended in a vehicle, across the surface of the optical glass to be ground. The workpieces are forced downward by pneumatic...

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...

Fresnel reflection refers to the reflection of light at the interface between two different media with different refractive indices. This phenomenon was named after the French engineer and physicist...

A method for measuring the index profile of an optical fiber by measuring the reflectance as a function of position on the end face.

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...

Optical fibers fused together to form a solid, vacuum-tight assembly in the form of a slab or rod. Discs or rectangular shapes having ground and polished surfaces perpendicular to the fiber lengths...

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...

A laser system consisting of a planar PN junction within a single crystal of gallium arsenide. The pair of parallel, semireflective end faces produces a Fabry-Perot resonant cavity, whereas the other...