Lambda Research Optics, Inc. - Limited Time Offer

Photonics Marketplace

Suppliers Products

Handbook Institutions Dictionary

Show Filters

Hide Filters

Type

DefinitionsAbbreviations/Acronyms

Browse by Letter

Opto Diode Corp. - Detector Spotlight 10-24 MR

PI Physik Instrumente - Microscope Stages HP ROS 11/24

8,726 terms

Photonics Dictionary

FORJ

fiber optic rotary joint

formate

A salt of formic acid that can be used to enhance the photosensitivity of silver halide crystals.

Förster resonance energy transfer

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...

forward bias

Voltage that produces current flow in the direction of lesser resistance to the steady-state direct current, i.e., from the anode to the cathode.

forward-looking infrared

A night-vision device that uses one or more infrared transducers to scan a scene in the 3- to 5-µm or 8- to 12-µm spectral region, convert the infrared radiation to electronic data and...

FOTP

fiber optic test procedure

FOTS

fiber optic transmission system

Foucault chart -> resolution target

A chart on paper or glass containing a series of sets of lines at progressively smaller spacing and used to ascertain the limiting number of lines per millimeter that an optical system is capable of...

Foucault knife-edge test

The Foucault test is performed by moving a knife edge laterally into the image of a small point source. The eye, or a camera, is placed immediately behind the knife edge, and the exit pupil of the...

Foucault prism

A polarizing prism formed from calcite that is like the Nicol prism but has the two parts divided by a thin air-film and cut to such angles that the extraordinary beam will be transmitted and the...

Foucault rotating mirror

A rotating mirror coupled with a distant mirror and used in a system by Foucault to compute the velocity of light. Light moving from the rotating mirror to the distant mirror and back was following...

four-level laser

A solid-state laser consisting of active atoms or ions of a transition metal, rare-earth metal or actinide, imbedded in a crystal or glass material, often garnet. Excitation and transfer to different...

four-wave mixing

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...

Fourier analysis

The representation of arbitrary functions as the superposition of sinusoidal functions whereby the representations themselves are referred to as Fourier series or Fourier integers.

Fourier images

The series of images formed when periodic objects are exposed to collimated monochromatic radiation and that result from Fresnel diffraction.

Fourier integers -> Fourier analysis

The representation of arbitrary functions as the superposition of sinusoidal functions whereby the representations themselves are referred to as Fourier series or Fourier integers.

Fourier transform hologram

A hologram formed by the recording of a plane object situated in the focal plane of a lens so that each object gives rise to a parallel beam of light incident on the plate. A collimated reference...

Fourier transform spectrometer

An instrument using a Michelson interferometer, a beamsplitter, two plane mirrors and a detector to give Fourier analysis of the detector signal to provide the desired spectrum.

Fourier transform

Any of the various methods of decomposing a signal into a set of coefficients of orthogonal waveforms (trigonometric functions).

FOV

field of view

fovea

The central portion of the retina that has the greatest sensitivity to form and color.

foveal vision -> photopic vision

Vision by means of retinal cones; color vision. Relatively high levels of luminance are required for photopic vision.

Fabry-Perot

focal plane

FPA

focal plane array; focal plane assembly

FPD

flat panel display; flame photometric detector

FPGA

field-programmable gate array

FPM

fine pointing mechanism

FPP

floating point processor

fps

frames per second; fixed pattern signal

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...

frame

1. To center an image or place it in any part of the television screen desired. Also applies to stills. 2. A single image of the connected multiple images on motion-picture film. 3. The size of the...

frame camera

A high-speed cine camera that produces discrete frames of a continuous event as opposed to the flow photographic record of a streak camera.

frame frequency

The number of times per second that the frame of a television system is completely scanned. In the United States, 30 per second is the standard frame frequency.

frame grabber

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 processing

In image processing, inclusive term for point and group processing.

frame rate

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...

framer

A device that permits the adjustment of facsimile transmitters and recorders so that their scanning lines stop and start at the same place in relation to the subject copy.

frames per second

The number of separate images exposed by a cine camera in a second or the number illuminated by a cine projector in a second. By varying the number of images recorded per second, films can be created...

Franck-Condon principle

The principle that electronic energy transitions occur at such speeds that the nuclei of the atoms in the molecular system remain stable during the transfers.

Franz-Keldysh effect

Observed lengthening in wavelengths of the optical absorption edge of a semiconductor with the application of an electric field.

FRAP

fluorescence recovery after photobleaching

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.

Fraunhofer hologram

A far-field pattern holographically reproduced image that is categorically considered with three-dimensional lensless photographs.

Fraunhofer lines

The dark absorption lines observed in the spectrum of the photosphere of the sun. There are thousands of these lines, the most prominent of which were observed and named by Fraunhofer early in the...

FRED

forward radar enhancement device

Fredholm integral

The mathematical formula that proves that any linear operator for which the impulse is known can be wholly characterized according to its impulse response.

free aperture -> clear aperture

The limited light-gathering area of an optical system. The area is normally restricted to an edge or outer surface of an individual component. Also known as free aperture or objective aperture. The...

free radicals

Short-lived molecular or atomic particles, with an unpaired electron, that play an important part in many photochemical reactions.

Photonics Dictionary

Need Help?