Photonics Dictionary: F

A bundle of optical fibers arranged randomly for the purpose of transmitting energy, not an image.

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

A tube containing mercury vapor and lined with a phosphor. When current is passed through the vapor the strong ultraviolet emission excites the phosphor, which emits visible light. The ultraviolet...

The series of rings when monochromatic light passes through a Fabry-Perot interferometer.

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...

Entirely analogous to color photography, but inclusive of light bands that do not appear in the visible spectrum.

The diffraction pattern of a source such as a light-emitting diode, injection laser diode or the output end of an optical waveguide observed at an infinite distance from the source.

The Faraday effect, named after the English scientist Michael Faraday, is a phenomenon in physics where the polarization plane of light is rotated when the light passes through a transparent medium...

In a birefringent material, the index of refraction varies with the direction of vibration of a lightwave. That direction having a low refractive index is the fast axis; at right angles to it is the...

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,...

The decrease of a component's efficiency, or a reduction in a material's light sensitivity, as the result of accumulated exposures to radiant energy.

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...

The principle that a light ray extending from one point to another will, after any number of reflections and refractions, follow the path requiring the least transit time. This is also known as the...

A prism with curved faces that collimates, reflects and refracts incident light. Often used in the production of spectrographs.

A fiber Bragg grating (FBG) is a type of optical filter that is inscribed or "written" into the core of an optical fiber. It consists of a periodic modulation of the refractive index along the length...

A rigid or flexible, concentrated assembly of glass or plastic fibers used to transmit optical images or light. See aligned bundle; incoherent bundle.

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 method of optical fiber coupling in which the fibers are ground down to expose their cores and placed together to allow light pulses to transfer from one to the other.

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 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 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 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 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 face of a cathode-ray tube (CRT) that has a fiber optic sheet attached to its surface. The sheet's fibers are at right angles to the face, allowing the transmittance of the fluorescent trace...

The use of thin flexible glass or plastic fibers as wave guides — or "light pipes" — to channel light from one location to another. Fiber optics is based off of the principle of total...

An optical recording technique that uses light source(s), a beamsplitting cube, light detector(s) and an optical fiber chronically implanted in animal brain to deliver excitation light to neurons...

A microscope in which laser light is delivered through single-mode fibers that replace the pinhole usually used in confocal microscopy. When the Gaussian mode is imaged from the fiber output onto the...

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...

1. A lens situated at or near the plane of an internal image to project the aperture of a previous objective or erector upon the aperture of a following lens. 2. A lens at or near the plane of a...

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...

The process by which the light from the images of photographic film is encoded into electrical signals for video transmission.

The necessary increase of a photograph's exposure time as the result of the additional absorption of light by the filter being used.

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 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 device used to measure the speed of light by adjusting the rotation of a toothed wheel so that light passing through one tooth opening is reflected through the next. This device has since been...

Any of a number of instruments that uses a flame to vaporize a solution of the chemical being analyzed so that light may be passed through the vapor. Monochromation of the transmitted light is...

The study of flames by means of a laser emitting blue light and a spectrometer to measure the green fluorescence created by the flame chemistry.