An erbium-doped fiber amplifier, or EDFA, is an optical repeater that amplifies an optical laser beam directly, bypassing opto-electronic and electro-optical (O/E and E/O) conversion. The EDFA uses a short length of optical fiber that has been treated or “doped” with the element erbium. When the laser that carries the signal causes the signal to pass through this fiber, energy is applied to boost, or amplify, the level of the signal.

An erbium-doped fiber amplifier, or EDFA, is an optical repeater that amplifies an optical laser beam directly, bypassing opto-electronic and electro-optical (O/E and E/O) conversion. The EDFA uses a short length of optical fiber that has been treated or “doped” with the element erbium. When the laser that carries the signal causes the signal to pass through this fiber, energy is applied to boost, or amplify, the level of the signal.