What is "plasma lamp"

n. A clear glass orb, filled with a mixture of various gases at low pressure, and driven by high frequency alternating current at high voltage.

Plasma lamps are a type of gas discharge lamp energized by radio frequency (RF) power. They are distinct from the novelty plasma lamps that were popular in the 1980s.

The internal-electrodeless lamp was invented by Tesla after his experimentation with high-frequency currents in evacuated glass tubes for the purposes of lighting and the study of high voltage phenomena. The first practical plasma lamps were the sulfur lamps manufactured by Fusion Lighting. This lamp suffered a number of practical problems and did not prosper commercially. These problems have gradually been overcome by manufacturers such as Ceravision and Luxim, and high-efficiency plasma (HEP) lamps have been introduced to the general lighting market. Plasma lamps with an internal phosphor coating are called external electrode fluorescent lamps (EEFL); these external electrodes or terminal conductors provide the radio frequency electric field.