Type

Browse by Letter

PI Physik Instrumente - Space Qualified Mirrors HP LW 5-6/24

234 terms

Photonics Dictionary: F

Clear All Filters x AC x F x
face-centered

With respect to a unit cell in a crystal structure, the property defining an atom located at the center of each face.

face-pumped laser

A device in which slab geometry internally compensates for thermal-optic distortion; the solid host material -- glass or Nd:YAG -- is in the form of a rectangular slab with plane parallel faces. The...

faceplate -> fiber optic faceplate

A plate made up of thousands of glass fibers arranged parallel to one another, i.e., in a coherent bundle, and fused together so that it is hermetically tight. It transfers an image from one plane to...

facet

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

facet erosion

The degradation of the facets in a laser diode due to the intensity of radiation.

facsimile chart

Data gathered by a facsimile system and converted into graphic, readable form; generally used in meteorology. Also known as fax chart or fax map.

facsimile machine

A device used to transmit and receive images that have been converted to electrical signals over regular telephone lines; it includes a scanner, a transmitter, a receiver and a printer.

facsimile radio

The conversion of a still picture into sound waves and its subsequent transmission by radio.

facsimile synchronizing

The maintenance of the same scanning relationship between the transmitting scanning spot and receiving scanning spot for each scanning line transmitted in a facsimile system.

facsimile

The reproduction of a picture or image, produced by scanning the image and converting it into electrical signals that carry the image to be reproduced. Also known as fax.

far-field diffraction pattern

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.

Faraday dark space

The nonluminous area that divides the negative glow from the positive column in a Crookes tube under conditions of moderate pressure.

feature extraction

In image processing and machine vision, the process in which an initial measurement pattern or some subsequence of measurement patterns is transformed to a new pattern feature. In image pattern...

feedback

The transfer of a part of a device's or circuit's output back to its input.

feedback amplifier

An amplifying device that returns a portion of its output to its input as a means of modifying the device's performance.

feedback circuit

A circuit that permits feedback in an electronic device.

feedback compensation

The placement of a device or an additional circuit into a feedback control system to improve its response in relation to a specific characteristic of the system.

feedback control system

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...

Fermi-Dirac function

The mathematical expression of the probability of any given state of energy being occupied when a semiconductor is in thermal equilibrium.

fiber distributed data interface

A standard for fiber optic data transmission systems being developed by the American National Standards Institute (ANSI) and associated working groups that will make fiber optic components from...

fiber optic faceplate

fill factor

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.

filter factor

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

fire cracks

Small clefts or fissures that penetrate the glass surface in the form of short-hooked crescents. Fire cracks result from a sudden excessive change in temperature.

first-surface mirror -> front-surface mirror

An optical reflector with the reflective coating applied to the front surface of the substrate. This eliminates the ghost image formed with second-surface mirrors.

flashback voltage

The inverse peak voltage that produces ionization in a gas tube.

flat machine

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

flat pack

A slab-shaped, very low profile package for electronic components; often used when printed circuit boards must be closely stacked together.

flux refraction

An alteration in the direction of the magnetic induction at the interface between two media of different permeability.

flyback

The time it takes a cathode-ray tube's electron beam to return to its starting point after completing one line, one field or one trace.

fractals

A method used to generate graphics within a computer system. Rather than dots or lines, fractal graphics work with mathematical formulas that represent the natural curves of the object.

fractional photothermolysis

A laser skin-resurfacing method that creates microscopic thermal wounds referred to as microscopic treatment zones (MTZs), which are surrounded by uninjured tissue. The MTZs are usually arranged in a...

Fraunhofer diffraction pattern -> far-field diffraction pattern

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.

free-abrasive machining

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...

free-space optical interconnect

A type of internal photonic connection in an integrated circuit in which a holographic grating is used to focus light at points on a silicon chip, maximizing the speed of signal propagation.

free-space optics

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...

Fresnel diffraction

1. Also known as near-field diffraction. The field of radiation sent through an aperture in an absorbing screen at large distances as compared with the wavelength and the dimensions of the aperture,...

front-surface mirror

An optical reflector with the reflective coating applied to the front surface of the substrate. This eliminates the ghost image formed with second-surface mirrors.

full-well capacity

The number of electrons that each pixel of a charge-coupled device can hold without overflowing and causing blooming.

furnace

See glass annealing furnace; glass melting furnace.

fax -> facsimile

The reproduction of a picture or image, produced by scanning the image and converting it into electrical signals that carry the image to be reproduced. Also known as fax.

fiber optic plate -> fiber optic faceplate

fiberless optics -> free-space optics

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...

full radiator -> blackbody

An ideal body that completely absorbs all radiant energy striking it and, therefore, appears perfectly black at all wavelengths. The radiation emitted by such a body when heated is referred to as...

F-center -> color center

A color center, in the context of materials science and condensed matter physics, refers to a specific type of crystallographic defect in a crystalline structure that introduces color to the...

Fabry-Perot cavity

An optical resonator in which feedback is accomplished by two parallel planes. In diode lasers, the planes are obtained by cleaving, polishing, etching, etc.

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...

Fabry-Perot method

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...

Fabry-Perot mirror

A highly reflective mirror that is usually flat on one surface and curved on the other, and that has silver, gold or aluminum deposited on glass, providing about 99 percent reflection.

false color

In imaging technology, assigning color to black and white images to differentiate features or convey information. Also called colorizing.

Photonics DictionaryF