Photonics Dictionary: P

A photomultiplier tube (PMT) is a highly sensitive vacuum tube that detects and amplifies low levels of light. It is widely used in various applications where high sensitivity, fast response times,...

In a camera or cathode-ray tube, distortion that is designated by a lateral skewing of the reproduced image.

An optical instrument designed to displace the line of sight in a vertical direction. For submarines and other military uses the periscope is a long tube containing prisms at both ends and...

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

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...

A photodetector, also known as a photosensor or photodiode, is a device that detects and converts light into an electrical signal. Photodetectors are widely used in various applications, ranging from...

The electron stream emitted by a phototube when the cathode is exposed to light.

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

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

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

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...

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

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

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

The photographic recording of data, in binary form, for storage in memory. Exposure is achieved by a cathode-ray tube or by modulating a continuous-wave laser beam with a Kerr cell, both relative to...

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

A photoelectrical relay that uses a phototube as its photoelectric device to open and close an electrical relay; used to activate counters and safety controls.

A term referring to the cathode-ray tube used in television receivers.

Philips trade name for a lead oxide low-light-level vidicon tube.

A medical imaging device that uses a ring of crystal/photomultiplier tube assemblies encircling the patient to detect gamma rays emitted by positrons colliding with electrons.

Laws that predict the maximum power output as a function of tube diameter for a hydrogen cyanide laser of a given discharge length and cavity losses, all other parameters being optimized.

A planar photocathode and a planar phosphor screen mounted in a close-spaced parallel configuration in an evacuated enclosure so that the ensemble of photoelectrons emitted from each photocathode...

A noncontact, nondestructive method of measuring defects in thin composite materials, using a xenon flashtube to generate heat in a sample. A thermal imaging system detects differences in the rates...

A process that employs heat to remove polyimide plastic coatings from silica optical fibers and capillary tubing.