- erbium-doped fiber amplifier (EDFA)
An optical fiber that can be used to amplify an optical input. Erbium rare earth ions are added to the fiber core material as a dopant in typical levels of a few hundred parts per million. The fiber is highly transparent at the erbium lasing wavelength of two to nine microns. When pumped by a laser diode, optical gain is created, and amplification occurs.