Photonics Dictionary

The photoemission that would occur if a crystal were pure and its structure perfect.

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.

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

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...

A photoemissive detector sensitive to wavelengths up to 1 µm. It has one sharp maximum of sensitivity at 350 nm and a broad maximum at 800 nm.

A photoelectric detector consisting of a glass tube internally coated with a low conductance material. Voltage applied along the tube causes photoemission from the photocathode at the end of the tube...

A photoemissive cell having an inert gas added to its envelope. Subsequent ionization of the gas increases the responsivity of the photocell.

A camera tube that employs a high-velocity electron beam to scan a photoemissive mosaic and to store electrical charge patterns.

One surface of a nonconducting plate that is coated with many minute particles of photoemissive material that are insulated from one another.

A photocathode having a P-type semiconductor with a work function less than its bandgap. The photocathode can release a hundredfold increase of photoemission in the infrared region.

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

A form of infrared CCD that utilizes internal photoemission as a photodetection mechanism.