Search
Menu
HIWIN Corp. - Linear Motor Stages LB 6/24
Photonics Marketplace
5,352 terms

Photonics Dictionary

Clear All Filters xIOs x
ultraviolet lens
A microscope used either to detect selective absorption of various wavelengths by the specimen or to achieve increased resolution by virtue of the short wavelength of ultraviolet radiation. Electron...
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 molecular nitrogen laser
A pulsed laser having molecular nitrogen as laser material and a wavelength output of 337 nm in the ultraviolet region. It is essentially a channel flashtube in which a pulse is applied to 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 photomicrography
The photographic recording that uses ultraviolet radiation to irradiate the microscope sample being examined and to form an image of the object on a photographic medium. The components of the...
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 spectrometer
A spectrophotometer designed for use in the 200- to 380-nm range of the electromagnetic spectrum and equipped with a calibrated scale to determine wavelength.
ultraviolet
That invisible region of the spectrum just beyond the violet end of the visible region. Wavelengths range from 1 to 400 nm.
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...
umbilical
A connection, typically made up of one or more cables, between a laser head and a separate power supply. Flexible pipes or hoses are sometimes used to protect and stabilize multiple cables.
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.
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.
underwater television system
A television system designed to obtain pictures of objects or scenes beneath the surface of the water. Generally, a low-light-level television camera and a suitable light source are enclosed in a...
undulator magnet
A device used in a free-electron laser to convert the electron-beam's energy into microwave laser radiation by creating a magnetic field of alternating polarity through which the free electrons are...
uniaxial crystal
A doubly refracting crystal having a single axis along which there is an absence of double refraction.
uniform luminance area
In a cathode-ray tube, the region wherein a display on the tube keeps 70 percent or more of its luminance at the center of the viewing area.
uniformly redundant array
Array used in coded-aperture imaging experiments with two-beam CO2 lasers that provide an artifact-free process, faithful reproduction of the true image, and more photon collection than the pinhole...
unijunction transistor
A three-terminal semiconductor having only one PN junction and a stable, open-circuit, negative-resistance property.
unit plane -> principal plane
In a lens or lens system, that surface at which the projections of an entering and exiting ray intersect. Also known as the equivalent refracting surface, the principal plane is most often not...
universal product code
A system by which consumer products are assigned a bar code that is read by a scanner at a cash register, enabling computerization of pricing and inventory records.
universal wavelength function
One of the four functions that allows the computation of a transparent medium's index of refraction, provided the index has been identified for four standard wavelengths.
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...
unpolarized
Behaving as though characterized by a series of waves having planes of vibration oriented at all possible azimuths.
upper rim ray -> rim ray
A ray of an image-forming bundle that passes through the edge of the entrance pupil or aperture stop. Usually used in connection with meridian rays, an upper rim ray is one that passes through the...
USAS-CSOCR
USA standard character set for optical character recognition
USITC
US International Trade Commission
USRA
University Space Research Association
USTA
US Telecommunications Association
UV
ultraviolet
UVFO
ultraviolet fiber optics
uviol glass
A type of glass contrived by Schott that is highly transparent to ultraviolet radiation.
v-coat
A multilayer antireflective thin-film coating, so called because its reflectance rises steeply at wavelengths above and below a narrow band at zero. The v-coat is particularly useful in high-power...
V-number -> normalized frequency
Also referred to as the V number in fiber optics; the normalized frequency is a dimensionless quantity, denoted by the symbol V, given by: where a is waveguide core radius, l is wavelength in vacuum,...
V-value -> Abbe constant
A dispersion relation defined in order to value the reciprocal amount of dispersion. It is defined as the refractivity over the difference in index values of the shortest and longest visible...
vacancy
In an ionic crystal, the region in the crystal lattice where the ion, predicted to be present, is absent.
vacuum
In optics, the term vacuum typically refers to a space devoid of matter, including air and other gases. However, in practical terms, achieving a perfect vacuum, where there is absolutely no matter...
vacuum apparatus
Equipment dependent on the effects of a vacuum. The principal applications in optics are in the coating of lenses and substrates and the fabrication of multilayer interference filters.
vacuum chamber
A vacuum chamber is a sealed enclosure from which air and other gases are removed to create a low-pressure environment, typically close to or at a complete vacuum. These chambers are often...
vacuum etching
Also known as cathodic etching. Surface etching achieved by bombarding an evacuated surface with gas ions.
vacuum phototube
A phototube that functions within a vacuum and thus eliminates the effects of gaseous ionization on its electrical properties.
vacuum spectrograph
A spectrograph that functions in a vacuum and therefore eliminates any air-absorption of the emission being surveyed.
vacuum spectrography
The technique of producing spectrograms in wavelengths beyond 120 nm by the use of a diffraction grating and a Schumann plate in a vacuum environment.
vacuum ultraviolet detector
A device that serves to detect the presence of vacuum ultraviolet radiation. It may be photographic film, a thermopile, ion chamber, vacuum photodiode, photomultiplier or channel electron multiplier.
vacuum ultraviolet radiation
Radiation whose spectrum runs between 100 and 300 nm. Any work with these wavelengths requires evacuated equipment.
vacuum ultraviolet source
Any source that emits radiation of wavelengths between 100 and 300 nm. Instruments used to study these sources must be evacuated, as vacuum ultraviolet does not travel freely in air.
vacuum ultraviolet spectroscopy
A method of spectral analysis using wavelengths between 100 and 300 nm that utilizes both emission and absorption techniques.
VAD
vapor axial deposition
Van der Waals
Van der Waals forces refer to the attractive or repulsive forces between molecules (or parts of molecules) that arise from fluctuations in electron distribution. These forces are relatively weak...
vanadate laser
Lasers based on neodymium-doped yttrium or gadolinium vanadate crystals. These include yttrium vanadate (Nd:YVO4), gadolinium vanadate (Nd:GdVO4), and lutetium vanadate (Nd:LuVO4). Vanadate lasers...

Photonics Dictionary

We use cookies to improve user experience and analyze our website traffic as stated in our Privacy Policy. By using this website, you agree to the use of cookies unless you have disabled them.