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AdTech Ceramics - Ceramic Packages 1-24 MR

3,163 terms

Photonics Dictionary

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transmissivity

The internal transmittance per unit thickness of a nondiffusing material.

transmitter

In fiber optic communications, a light source whose beam can be modulated and sent along an optical fiber, and the electronics that support it.

transparent electrophotographic films

Imaging materials that generally consist of a polyester base, a transparent electrically conductive layer and an organic photoconductive top coating. When charged and exposed to light, an...

transposition

In optics, the changing of the relative curves of a lens without changing its refractive value.

transverse electric mode -> transverse mode

In the context of optics and lasers, a transverse mode refers to a specific spatial pattern of the electric field within the cross-section of a laser beam. These modes represent the different...

transverse electromagnetic mode -> transverse mode

In the context of optics and lasers, a transverse mode refers to a specific spatial pattern of the electric field within the cross-section of a laser beam. These modes represent the different...

transverse mode

In the context of optics and lasers, a transverse mode refers to a specific spatial pattern of the electric field within the cross-section of a laser beam. These modes represent the different...

transverse offset method

A technique used to measure the mode-field diameter of an optical fiber by scanning one fiber past another at a distance of five microns or less.

transverse scattering

The method for measuring the index profile of an optical fiber or preform by illuminating it coherently and transversely to its axis, and examining the far-field radiation pattern.

transversely excited atmosphere carbon dioxide laser

Abbreviated TEA CO2 laser. A gas laser that provides shorter pulses and higher peak powers than conventional CO2 lasers. The electrical excitation pulse occurs transversely to the optical axis...

trapped mode -> 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.

traveling microscope

A measuring instrument composed of a microscope and reticle, and mounted on a calibrated slide mechanism. May be used accurately to determine the distance between objects being viewed.

traveling wave phototube

A traveling wave tube (TWT) containing a photocathode and window that, receiving a laser beam, produces a modified photoelectric current that is accelerated and propagated into its helical frame.

trichromacy

The basis of color vision in the human eye. Three types of cones have been identified, each having a unique spectral response (red, green and blue).

triplet

A lens assembly made up of three lens elements that may or may not be cemented.

tristimulus colorimeter -> colorimeter

A colorimeter is a device used to measure and quantify the color characteristics of an object or a light source. It provides objective and standardized color information, typically expressed in terms...

trunk

In a fiber optic communications network, a circuit that connects two switching centers and does not branch off to terminal points.

tungsten lamp

An evacuated bulb containing a tungsten filament that is heated by passing an electric current through it. In domestic light bulbs the inside of the bulb is frosted to soften shadows. In projection...

tunneling

An observed effect of the ability of certain atomic particles to pass through a barrier that they cannot pass over because of the required energy level, based on a law of quantum mechanics that...

tunneling mode -> leaky mode

In an optical waveguide, a mode whose field decays monotonically for a finite distance in the transverse direction but which becomes oscillatory everywhere beyond that finite distance.

turbidity

Turbidity is a measure of the cloudiness or haziness of a fluid caused by the presence of suspended particles. These particles can include sediment, silt, clay, plankton, and other microscopic...

turret

A rotating plate containing two or more lenses to provide a rapid interchange.

twisted intramolecular charge transfer

Twisted intramolecular charge transfer (TICT) is a phenomenon observed in certain organic molecules containing electron-donor and electron-acceptor groups that are linked together within the same...

two-photon excited fluorescence

Two-photon excited fluorescence (TPEF) is a nonlinear optical method that allows imaging of biological cells and living tissue. The advantage of TPEF in comparison to conventional fluorescence...

two-photon fluorescence

This results from the simultaneous absorption of two photons, each having half the energy needed for excitation and requiring a high spatial and temporal concentration of photons. The ensuing...

two-photon polymerization

Two-photon polymerization (TPP) is a technique used in additive manufacturing, specifically in the field of 3D printing. It involves using a focused laser to polymerize a photosensitive material in a...

two-six

Referring to compound semiconductor materials combining one element with two valence electrons and one or more with six. Examples include beryllium oxide and zinc selenide. (II-VI).

Twyman-Green interferometer

A testing device that provides a contour map of the emergent wavefront for the observer in terms of the given wavelength of the light.

Twyman-Green interferometry

Twyman-Green interferometry is a technique used in optics to measure the flatness or surface profile of optical components with high precision. It is based on the principles of interference of light...

uhlbricht sphere -> integrating sphere

A hollow sphere coated internally with a white diffusing material and provided with openings for incident beam, specimen and detector used for measuring the diffuse reflectance or transmittance of...

ultrafast pulsed laser

An ultrafast pulsed laser is a type of laser that emits extremely short pulses of light with durations typically on the order of femtoseconds (10-15 seconds) or picoseconds (10-12 seconds). These...

ultrashort-pulse laser

A laser capable of generating light pulses that last only a few femtoseconds. This can be achieved by nonlinear filtering to increase bandwidth and compress the pulse or by passive mode-locking or...

Ultraviolet-C

Ultraviolet-C (UV-C) refers to a specific range of ultraviolet radiation with shorter wavelengths than those of visible light. UV-C radiation spans the electromagnetic spectrum with wavelengths...

ultraviolet densitometry

A technique, involving spectrophotometry in the ultraviolet, that is designed to determine the colors of thin-layer chromatographic absorbents after elution.

ultraviolet fiber optics

Ultraviolet (UV) fiber optics refers to optical fibers that are designed and optimized for the transmission of ultraviolet light, which is electromagnetic radiation with wavelengths shorter than...

ultraviolet microscopy

The study and photographing of microscope specimens in ultraviolet light; using an optical microscope containing fluorite and quartz components to efficiently image wavelengths much shorter than the...

ultraviolet photoemission spectroscopy

A technique for measuring the energy spectrum of electrons emitted during the absorption of ultraviolet radiation. This spectrum reveals the characteristic ionization energies of the molecules and...

ultraviolet reflectance

Ultraviolet reflectance refers to the ability of a material or surface to reflect UV light. Ultraviolet light is electromagnetic radiation with wavelengths shorter than those of visible light,...

ultraviolet-visible spectrometer

Also known as UV-VIS spectrometer, a device that measures the absorbance, reflectance or transmittance of light in the ultraviolet or visible wavelengths absorbed, reflected or transmitted. Commonly...

umbra -> penumbra

A source of light will not cast a distinct shadow of an interfering, opaque object, but will cast a shadow having two parts: 1. the umbra, or the central, totally dark part of the shadow; and 2. the...

unblanking

The initiation of the beam in a cathode-ray tube.

uncut

A term describing lenses with both surfaces finished but not yet cut to any form.

underillumination

Illumination of hologram facets with a beam that covers only a small portion of the hologram in order to optimize laser energy use. See overillumination.

unmanned aerial vehicle

An unmanned aerial vehicle (UAV), commonly known as a drone, is an aircraft without a human pilot onboard. UAVs are remotely controlled or autonomously operated, and they can be used for various...

UOE

unit of error

UPC

universal product code

URA

uniformly redundant array

USAS-CSOCR

USA standard character set for optical character recognition

USB

universal serial bus

USRA

University Space Research Association

Photonics Dictionary

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