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Excelitas PCO GmbH - Industrial Camera 11-24 VS MR

Meadowlark Optics - Wave Plates 6/24 MR 2024

8,726 terms

Photonics Dictionary

group velocity

For a particular mode, the reciprocal of the rate of change of the phase constant with respect to angular frequency.

grown-junction photocell

A photodiode that has been designed so that the bar of semiconductor material has a PN junction perpendicular to its length and an ohmic contact at each of its ends.

GSC

gas-solid chromatography

GSE

grating surface emitting

GSGG

gadolinium scandium gallium garnet

GSP

graphics system processors

GTC

gain time constant; gain time control

GTI

Gires-Tournois interferometer

GTL

gas transport laser

Gudden-Pohl effect

The light flash that occurs when an electrical field is applied to a phosphor already excited by ultraviolet radiation.

GUI

graphical user interface

guide factor

A factor derived by equating the incident light on the subject to the required incident light for suitable photography. The lamp-subject-distance then is multiplied by the aperture and solved in...

guided mode

In an optical waveguide, a mode whose field decays monotonically in the transverse direction everywhere external to the core and which does not lose power to radiation. Also called bound mode.

guided ray

In an optical waveguide, a ray that is completely confined to the core.

guided wave

A wave in which energy is focused near a boundary separating materials having different properties. Propagation of the wave is in a direction parallel to the boundary.

gun camera

A camera accurately aligned to a weapons system to provide a photographic record of system performance.

gunsight

An optical device that permits the alignment of a gun, cannon or rocket launcher system with its target.

GVD

group velocity dispersion

gigawatt

gray

gyroscope

A gyroscope is a mechanical device consisting of a spinning disk or wheel mounted on a spinning axis in such a way that its orientation remains fixed regardless of any movement of its mounting...

gyroscopic camera mount

A mount that uses a floating suspension and a motor-driven gyroscope to keep a motion picture or still camera at a set angle even though the camera is mounted in a place that subjects it to heavy...

gyroscopy

Gyroscopy refers to the principles and applications of gyroscopes, devices that measure or maintain orientation based on the principles of angular momentum. Gyroscopes are essential in various...

henry; hecto-; hour; Planck constant

H-plane bend

With respect to waveguides, the continuous change in the direction of the axis of the wavelength, during which the axis is perpendicular to the direction of polarization.

hackle

A defect in the cleaved end face of an optical fiber, defined as multiple surface irregularities across the fiber surface. A less serious imperfection of the same nature is known as mist.

HADAR

heat-assisted detection and ranging

Haidinger fringes

Also known as constant angle or constant deviation fringes. The interference fringes observed with dense flat plates near normal incidence. The fringes of the Fabry-Perot interferometer are Haidinger...

hair-trigger operation

Triggering a laser at a predetermined time by pumping it to a level just below its threshold and then using an auxiliary source that quickly pumps it above threshold. Means of achieving it in laser...

halation

1. In a cathode-ray tube, the glow surrounding a bright spot that appears on the fluorescent screen as the result of the screen's light being reflected by the front and rear surfaces of the tube's...

half bandwidth

The term half bandwidth (HBW) generally refers to the width of a spectral band or frequency range at half of its maximum amplitude. It is commonly used in the context of signal processing, optics,...

half duplex

A communications system that can transmit in only a single direction at a time. See duplex.

half silvered

Describing a surface that is coated with a film of metal of such thickness that it transmits about one-half of the incident light and reflects about one-half.

half wave

Refers to half a wave cycle.

half-power point

1. The value on either the leading or the trailing edge of a laser pulse at which the power is one-half of its maximum value. 2. The wavelength at which a filter is transmitting one-half of its peak...

half-shade device

A device for forming at least two adjacent areas of polarized light. The angle between the directions of vibration of the light waves in the two areas is generally small.

half-shade plate

A semicircular, half-wave quartz plate between the polarizer and analyzer. It often is used in forming precision settings with a polariscope.

half-wave plate

A plate of electro-optical material that serves to rotate the plane of polarization of a light beam.

half-wave voltage

That voltage required across a Pockels, Kerr or other electro-optic light modulator to retard one polarization electrical vector by one-half a wavelength relative to the other. It corresponds to a...

halftone screen

A plate containing a uniform pattern of transparent holes in an opaque background, the clear area being nearly equal to the opaque area. Used in the printing process.

halftones

The gray-colored tones halfway between shadows and highlights in a reproduced image.

halide

In chemistry, a halide refers to a chemical compound containing one or more halogen atoms bonded to another element. The halogens are a group of elements in the periodic table that includes fluorine...

Hall effect

The development of a transverse electric field in a solid material when it carries an electric current and is placed in a magnetic field that is perpendicular to the current.

halo

1. The faintly hued ring that is seen to surround a light source viewed through fog or light clouds. The size of scattering particles determines the size of the ring. 2. The ring surrounding a...

HALO

high-altitude large optics

halogen

Any of the five elements astatine, chlorine, fluorine, bromine and iodine, grouped because their chemical properties are similar.

halogen lamp

A halogen lamp, also known as a tungsten halogen, quartz-halogen, or quartz iodine lamp, is an incandescent lamp that uses a tungsten filament surrounded by a small amount of halogen gas, such as...

HALT

highly accelerated life test

halving line

The line that divides the two half-images in a coincidence rangefinder. The two halves of the images formed by the two objectives of the instrument must be brought to a point where they coincide...

hand viewer

A device small enough to be held in a hand that uses a magnifying lens and a translucent back to permit the viewing of photographic transparencies.

Photonics Dictionary

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