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Zurich Instruments AG - Boost Your Optics July-August HP

743 terms

Photonics Dictionary: P

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photoelectric densitometer -> densitometer

1. An instrument used to measure the opacity or density of dyes, pigments or dispersed particles that form an image in or on a medium, such as a photographic film. 2. A device used to measure the...

photoelectric effect

The emission of an electron from a surface that occurs when a photon impinges upon the surface and is absorbed. This effect is the means by which photons may be detected.

photoelectric emission

The electron emission from a substance or instrument whose surface has been bombarded by a suitable amount of radiation.

photoelectric exposure meter

A device consisting of a microammeter, a photovoltaic cell and a battery. It is used for the measurement of scene brightness and the determination of correct exposure for photographic processes.

photoelectric fluorometer

A filter fluorometer that uses a photomultiplier tube to detect the fluorescence of a sample.

photoelectric mixing

Also known as light beating. The mixing of two narrowband optical components to produce an AC component in the photocurrent at the optical difference frequency.

photoelectric multiplier

A phototube in which the primary photoemission current, before being extracted at the anode, is multiplied many times.

photoelectric photometer

Also known as electronic photometer. A photometer with a photocell, phototransistor or phototube for measuring the intensity of light.

photoelectric photometry

The use of photoelectric sensors to detect and measure the intensity of a light source. This application, as compared to human observation, results in higher speeds of operation, a greater...

photoelectric pyrometer

An instrument used to measure the temperature of a source through the use of photoelectric cells to detect and measure the intensity of the light emitted by the source.

photoelectric reader

An input device for a computer that detects and reads the data, in the form of punched holes in cards, by light that is transmitted through the holes.

photoelectric receiver

An instrument that uses a photocell to detect and measure the intensity of incident light.

photoelectric reflectometer

A photoelectric photometer used to measure the reflectance of a surface.

photoelectric relay

A relay that opens or closes an electrical circuit depending on the intensity of the light incident to a photoelectric device contained in the relay.

photoelectric scanner

A system mounted a few inches above a moving plane that consists of a light source, lenses and one or more phototubes. In this position, the scanner actuates the control equipment when the quantity...

photoelectric sensitivity

That property of a material that determines its ability to release electrons when absorbing photons.

photoelectric spectrophotometer

A system that consists of a spectrophotometer with a photoelectric detector for measurement of radiant energy.

photoelectric tube -> phototube

An electron tube having a photocathode for the emission of a photoelectric current.

photoelectromagnetic effect

Interaction of a magnetic field with a photoconductive substance exposed to light to create a potential difference.

photoelectromotive force

The force that stimulates the emission of an electrical current when photovoltaic action creates a potential difference between two points.

photoelectron holography

A technique proposed for studying the atomic structure of crystals by measuring the interference pattern generated when the crystal is illuminated by a burst of finely tuned x-rays. The resulting...

photoelectron microscopy

Surface analysis by means of photon induced electron emission. PEM methods provide high lateral resolution of the observed sample.For surface material sciences PEM allows the investigation of...

photoelectron

Electron released in photoelectric activity.

photoemission -> photoelectric emission

The electron emission from a substance or instrument whose surface has been bombarded by a suitable amount of radiation.

photoemissive cell -> photoemissive detector

An electronic tube instrument in which the anode current varies with the intensity of light incident on the cathode.

photoemissive detector

An electronic tube instrument in which the anode current varies with the intensity of light incident on the cathode.

photoemissive effect -> photoelectric effect

The emission of an electron from a surface that occurs when a photon impinges upon the surface and is absorbed. This effect is the means by which photons may be detected.

photoemissive tube photometer

A photometer that uses a photoemissive tube to detect and measure light. See photoelectric photometry.

photoemulsion

In photolithography, an opaque material used in masks that has a lower optical density and grainier composition than chrome.

photofabrication

The use of photoetching techniques to produce small tools, parts and dies from sheet metal.

photoglow tube

A particular type of phototube having increased sensitivity as a result of the glow initiated by light incident to the cathode.

photogrammetric equipment

The special cameras, film and other means for forming maps by aerial photography.

photogrammetry

Photogrammetry is a technique used to obtain accurate three-dimensional measurements of objects and environments through the analysis of photographs or imagery. It involves extracting information...

photographic dosimetry

The use of photographic emulsions to detect and determine the amounts of ionizing radiation, such as x-rays and gamma rays, in an area. This is accomplished by exposing the emulsion to the radiation...

photographic exposure

The product of exposure time and irradiance or illuminance.

photographic field

The maximum angle of view that can be recorded by a camera. Field is a function of lens focal length and film format.

photographic photometry

A form of photometric measurement, often used with light sources that are transparent or fluctuating, in which a photographic plate is used to obtain a record of a source's relative intensities over...

photographic radiometry

The use of photographic recording equipment to measure radiant energy. With this procedure, many measurements of radiant energy can be recorded simultaneously and permanently.

photographic resolution

A measure of the ability of a photographic system to record fine detail. Usually stated in terms of cycles per millimeter on the processed film.

photographic sensitometer -> sensitometer

An instrument for determining the sensitivity of a photographic film to light. The film is given either a stepped exposure or a continuously varied exposure; after processing, the density is measured...

photographic sensitometry

The measurement of the responsivity of photographic media and of the relations between exposure and density of developed images.

photographic shutter efficiency

A measure of the total light passed by a shutter during an exposure, compared with the light that could be passed by an idealized, infinitely fast shutter fully open for the same extreme time.

photographic sound recorder

A system in which the electrical signal embedded within an audio input signal is converted to a modulated light pattern and recorded on film.

photographic thermometry

The photographic recording of the heat radiation emitted from various points on the object as corresponding density variations on fast infrared film.

photoimmunotherapy

Photoimmunotherapy (PIT) is a medical treatment approach that combines elements of phototherapy and immunotherapy to target and treat specific cells or tissues in the body. The key components of this...

photoionization

The ionization that occurs in gas affected by the action of radiation quanta.

photoisolator -> 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...

photolithography

Photolithography is a key process in the manufacturing of semiconductor devices, integrated circuits, and microelectromechanical systems (MEMS). It is a photomechanical process used to transfer...

photoluminescence mapping

A technique used for noncontact inspection of semiconductor wafers. The material is illuminated by an excitation source that stimulates photoluminescence; the resulting spectrum is analyzed, yielding...

photoluminescence

Photoluminescence is a phenomenon in which a material absorbs photons (light) at one wavelength and then re-emits photons at a longer wavelength. This process occurs when electrons in the material...

Photonics DictionaryP