Tele-Communication (Telecom) Terms Glossary and Dictionary
EDFA: Erbium-Doped Fiber Amplifier
Erbium-Doped Fiber Amplifier (EDFA), also called optical amplifier or an erbium amplifier, is an optical or IR repeater that amplifies a modulated laser beam directly, without opto-electronic and electro-optical conversion. The device uses a short length of optical fiber doped with the rare-earth element erbium. When the signal-carrying laser beams pass through this fiber, external energy is applied, usually at IR wavelengths. This so-called pumping excites the atoms in the erbium-doped section of optical fiber, increasing the intensity of the laser beams passing through. The beams emerging from the EDFA retain all of their original modulation characteristics, but are brighter than the input beams.