Photonics Dictionary

Also referred to as a bulb. The glass housing that encloses an incandescent source, or the glass or metal housing that encloses an electron tube.

Distortion caused by variations in the rate of change of phase shift with frequency over the signal's necessary bandwidth.

Envelopes for cathode-ray tubes are made by blowing glass in the same manner as light bulbs. They have a fairly flat end face to carry the phosphor material applied internally.

The method of disintegrating the substance of the cathode by bombarding it with ions and depositing it on another electrode or electron tube envelope.

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

Gram-negative bacteria are a group of bacteria that possess a cell envelope composed of a thin layer of peptidoglycan surrounded by an outer membrane. This outer membrane contains lipopolysaccharides...

A halogen lamp, also known as a tungsten halogen, quartz-halogen, or quartz iodine lamp, is an incandescent lamp that uses a tungsten filament surrounded by a small amount of halogen gas, such as...

An electro-optic system using, in general form, an evacuated glass envelope with a semitransparent photocathode at one end and a luminescent screen at the other for the amplification of an optical...

A camera tube widely used in television broadcasting. It consists of three sections within a single vacuum envelope. 1. A photosensitive film sometimes called the photocathode. The scene to be...

A development aimed at extending the life of a tungsten filament. The iodine vapor in the lamp envelope combines with the tungsten vapor emitted by the hot filament, but the compound is decomposed by...

A laser in which the transition involved in stimulated emission of radiation takes place between two levels of an ionized gas. The gases are electrically excited in a container called a plasma tube,...

A light source, such as the sun or an incandescent lamp, that freely penetrates ordinary glass bulbs and emits in the near-ultraviolet (wavelengths ranging from about 300 to 400 nm). A mercury vapor...

Power modulation refers to the intentional variation of power levels in a signal, often in the context of electronic communication systems. This modulation technique is used to encode information...

A lamp with a quartz envelope that transmits radiation generally rich in the ultraviolet.

In optical emission spectroscopy, the reduction in radiant power in the central portion of spectral lines arising from the selective absorption by the cooler outer vapor of the source envelope of...