Photonics Dictionary

Etaloning is an optical phenomenon that occurs in imaging systems, particularly in devices such as spectrometers, interferometers, and cameras. It is characterized by the appearance of interference...

An event-based image sensor, also known as a dynamic vision sensor (DVS), is a type of digital imaging device designed to capture visual information in a highly efficient and unique way compared to...

Excimer laser coronary angioplasty (ELCA) refers to a medical procedure used in the treatment of coronary artery disease. This technique involves the use of an excimer laser to perform angioplasty, a...

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...

A single-anode mercury pool tube that is designed to maintain a continuous cathode spot.

Wavelengths between 400 and 1400 nm (VIS to NIR) are focused onto the retina by the cornea. Because the retina is sensitive to light, these wavelengths can be damaging even at low energies. It is the...

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 nonabsorbing, multireflecting device, similar in design to the Fabry-Perot interferometer, that serves as a multilayer, narrow-bandpass filter.

A FAC lens, or fast axis collimation lens, is an optical component used in laser diode systems to collimate the fast axis of laser emission. Laser diodes emit light in two main axes: the fast axis,...

A system designed to control the output quantity of a device by returning a portion of its output signal to its input. This results in the manipulation of the input quantity so that the desired...

A femtosecond laser is a type of laser that emits ultrashort pulses of light with durations on the order of femtoseconds, where one femtosecond is equal to 10-15 seconds. These lasers are capable of...

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 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 imaging bundle is a specialized optical device composed of multiple optical fibers bundled together. Each fiber optic strand within the bundle acts as a conduit for transmitting light....

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...

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 transformer that is designed to regulate the amount of current that passes through an electron tube's filament.

In solar energy technology, the percent of usable land covered by collectors. The horizontal collector is the only design that exhibits 100 percent fill factor.

A mechanism in a camera designed to position the film in the focal plane for exposure.

An instrument designed to place nongraphic information, usually generated by a computer, onto photographic film. The information is generally encoded as a series of opaque and translucent spots, or...

An interferometer spectrometer designed to measure thicknesses of thin films or layers by recording the interferogram and by having a computer within the instrument to establish the distance between...

A fixed-focus camera designed to record the ink impression of fingerprints that have been impressed on a card or form for record purposes.

A device that is designed to automatically turn electric lamps on and off in a rapidly repeating sequence. The device may use a motor-driven mechanism or a combination heater filament and bimetallic...

A polishing machine designed to permit adjustment of the polisher speed and motion for the control of flat surfaces.

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...

An instrument designed to give a visual indication to the pilot when the plane has strayed from a specific flight path.

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 lens having an extremely high aperture and used in the recording of x-ray fluorescent screen images. It often is specially designed for the camera, the color of the light and the image...

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 form of image intensifier designed to amplify a weak fluoroscopic image. The image is received at an input phosphor screen, as opposed to the light-sensitive electrode emitter used in regular image...

An incandescent or carbon arc lamp designed with a stable and compact arc or filament that permits it to be used as a light source to be focused by a lens system.

A phenomenon that occurs in WDM and DWDM systems when three closely spaced signal wavelengths near the zero-dispersion wavelength interact with each other, producing a fourth wavelength that...

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...

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...

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...

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...

The lowest order mode of a waveguide. In fibers, the mode designated LP01 or HE11.

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 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...

An optical instrument designed for the visual examination of the inside of the stomach.