AdTech Ceramics - Ceramic Packages 1-24 LB

Photonics Marketplace

Suppliers Products

Handbook Institutions Dictionary

Show Filters

Hide Filters

Type

DefinitionsAbbreviations/Acronyms

Browse by Letter

Excelitas PCO GmbH - PCO.Edge 11-24 BIO MR

8,726 terms

Photonics Dictionary

phase-locked loop

A circuit that uses feedback to synchronize the phase of a voltage-controlled oscillator with the phase of an incoming or reference signal.

phase-modulated sensor

A phase-modulated sensor is a type of sensor that uses modulation of the phase of a signal to measure changes in a physical quantity. In such sensors, variations in the phase of the signal are...

phase-only filter

A type of matched filter that responds only to the phase of incoming light; the output has a much greater intensity than that of a classical matched filter, which responds to phase and amplitude. The...

phase-shift keying

A method of coding information in a communications system where the shift in the phase of an electromagnetic wave represents a particular bit or character.

PHB

photochemical hole burning

PHD

pulse height distribution

phenotype

In biology, particularly genetics and evolutionary biology, the phenotype refers to the observable characteristics or traits of an organism, resulting from the interaction of its genetic makeup...

Philips ionization gage -> Penning discharge

A standard source of high-charge-state ions for accelerators that has an external magnetic field oriented perpendicularly to the two cathode faces. Also called Philips ionization gauge.

phluometry

The term applied to the geometrical structure of radiometry or of the propagation of any quantity that is conversed and that travels in straight lines at velocities characteristic of the medium.

phonon

A phonon is a quantum of vibrational energy associated with the periodic motion of atoms or molecules in a crystalline lattice. In simpler terms, phonons are quanta of lattice vibrations in a solid...

phosphate glass

A type of glass that includes phosphorus pentoxide and that, unlike silica-based glass, is resistant to hydrofluoric acid.

phosphor

A chemical substance that exhibits fluorescence when excited by ultraviolet radiation, x-rays or an electron beam. The amount of visible light is proportional to the amount of excitation energy. If...

phosphor dots

Very small phosphor particles present on the screen of a picture tube.

phosphor light source

A source made to glow by electrons that are produced either electrically or by isotopes of various elements.

phosphor persistence

The property of a phosphor that determines its ability to emit light for a time after the stimulus has been extinguished. Persistence may extend to over a minute.

phosphor thermometry

A method for remote measurement of the temperature of moving surfaces in harsh environments by using a laser to stimulate fluorescence of thermographic phosphors and then measuring the decay times by...

phosphorescence

Luminescence is the emission of light from a source that is delayed by more than 10-8 s following excitation.

phosphorescence spectroscopy

The spectroscopic study of the radiation emitted by the lifetime of phosphorescence.

phosphorography

A process used in pyrometry and photothermometry to create a photographic record of a surface's temperature gradients. Essentially, it involves the exposure of a glowing phosphorescent surface to the...

photoacoustic calorimetry

Periodic interruptions of a light beam incident on an absorbing medium that produce heat, expansion and acoustic wave generation. Since the amplitude of this wave is proportional to the absorbed...

photoacoustic gas cell

A device for measuring absorption coefficients in which a confined, nonabsorbing gas fills the space inside the cell between the two windows, which are made from a weakly absorbing medium.

photoacoustic imaging

Abbreviated PAI. An imaging modality with a hybrid technique based on the acoustic detection of optical absorption from endogenous chromophores or exogenous contrast agents. Light is absorbed by the...

photoacoustic spectroscopy

A method for obtaining the optical absorption spectra of solids, semisolids, liquids and gases. PAS is inherently insensitive to reflection or scattering from the sample, analyzes opaque samples and...

photoacoustic

Photoacoustic refers to the generation of acoustic (sound) waves following the absorption of light (usually laser pulses) by a material. This phenomenon occurs when light energy is absorbed by a...

photobiomodulation

A light therapy that utilizes nonionizing light sources, including lasers, LEDs, and broadband light, in the visible and infrared spectrum. It is a nonthermal process involving endogenous...

photobleaching

Photobleaching is a phenomenon in which the fluorescence of a fluorophore (a fluorescent molecule or dye) is permanently reduced or eliminated upon prolonged exposure to light. This process occurs...

photocathode luminous sensitivity

The responsivity of a photocathode to luminous energy equal to the ratio of the photoelectric emission to the incident luminous flux.

photocathodes

Photocathodes are specialized materials or surfaces that exhibit the photoelectric effect, wherein the absorption of photons leads to the emission of electrons. When photons with sufficient energy...

photocell -> detector

1. A device designed to convert the energy of incident radiation into another form for the determination of the presence of the radiation. The device may function by electrical, photographic or...

photochemical

The term photochemical pertains to chemical processes or reactions that are initiated or influenced by the absorption of light. Photochemical reactions involve the interaction of light, often in the...

photochemical detector

An instrument used to detect and measure radiant energy by the formation of a chemical reaction.

photochemical hole burning

A method of producing disks for erasable optical data storage. Information is recorded by a laser beam that generates pits on the surface of the disk while it is being cryogenically cooled. Erasure...

photochemistry

The study of chemical reactions stimulated by the properties of light.

photochromatic compound

A chemical compound that exhibits a reversible change in its absorption spectrum upon irradiation with given wavelengths of light.

photochromatic interval

The discrepancy between the absolute luminance threshold and the photochromatic threshold.

photochromic

Photochromic refers to a property exhibited by certain materials, typically organic compounds or dyes, which undergo reversible changes in color when exposed to light. Specifically, photochromic...

photochromism

The reversible change in the absorption spectrum of certain compounds upon irradiation with a given wavelength of light.

photoclinometer

A photographic recording instrument that measures deviation from the vertical of a drilled well or mine.

photocoagulator

An optical medical instrument that uses an intense, precisely focused beam of light to stop weakened blood vessels from hemorrhaging. The thermal effect of the beam strengthens the weakened vessels...

photoconductive antenna

Photoconductive antenna (PCA) is a semiconductor element that generates or detects high-frequency electromagnetic signals. Compact PCAs based on gallium arsenide (GaAs) or indium gallium arsenide...

photoconductive cell -> photoconductive detector

A device for detecting visual and infrared radiation using a photoconductor as the principle sensing element.

photoconductive detector

A device for detecting visual and infrared radiation using a photoconductor as the principle sensing element.

photoconductive effect

The alteration of electric conductivity produced by the absorption of varying amounts of radiation composed of photons.

photoconductive film

A film of material that exhibits varying conductivity based upon its absorption of varying amounts of photon radiation.

photoconductivity

The conductivity increase exhibited by some nonmetallic materials, resulting from the free carriers generated when photon energy is absorbed in electronic transitions. The rate at which free carriers...

photoconductor contact

Material used to integrate photoconductors into electro-optical systems. It should provide low resistance to the flow of charge, avoid recombination of the charge carriers, inject only majority...

photoconductor

A light-sensitive resistor in which resistance decreases with increase in light intensity when illuminated. The device consists of a thin single-crystal or polycrystalline film of compound...

photocoupler -> optoisolator

An optical coupling device that uses light to bridge the gap between incompatible wire communications systems. It contains an input amplifier, a light-emitting diode, a photodiode and an output...

photocurrent

The current that flows through a photosensitive device, such as a photodiode, as the result of exposure to radiant power.

photodarkening

The effect that the optical losses in a medium can grow when the medium is irradiated with light at certain wavelengths.

<
1
2
3
...
119
120
121
122
123
...
173
174
175
>

Photonics Dictionary

Need Help?