Photonics Dictionary

A vacuum tube with an electron gun at one end and a fluorescent screen at the other. Electrons emitted from a heated filament are accelerated by a series of annular anodes at progressively higher...

The progressive defocusing of a cathode-ray tube display image that occurs when the deflected electron beam impinges on the cathode-ray tube screen at a slant.

A shutter having one or more roller blinds of material with a variable slit that moves across the back of the camera when released and exposes the sensitized material progressively.

Transparencies that represent progressive steps in the amount of transmitted radiation for administering predetermined amounts of radiation to a radiation-sensitive substance. The steps are...

A metal tool used to grind lenses with loose abrasive (see diamond cutting tool). The functional surface of the lap is carefully formed to be opposite the curve to be produced on the glass (concave...

Prediction based on observations of nuclear masses in the valley of stability that indicates the maximum number of electrons that will bind with a given number of protons in progressive order along...

A chart on paper or glass containing a series of sets of lines at progressively smaller spacing and used to ascertain the limiting number of lines per millimeter that an optical system is capable of...

A camera system used for microphotography that has a structure, such as a cylinder or surveyor belt, to rotate the documents to be recorded. The image is fixed relative to film motion and exposure is...

An optical compensator similar to the Babinet compensator, but which produces a phase-change consistent throughout its field, as opposed to the Babinet's phase-change, which occurs progressively...

An optical filter so constructed that the density increases progressively from one end to the other, or angularly around a circular disc.