Photonics Dictionary: P

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

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 cathode principally designed to emit a photoelectric current.

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

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

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

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,...

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 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...