EDFA (Erbium-Doped Fiber Amplifier)

An EDFA is an optical amplifier that uses a section of erbium-ion-doped fiber to amplify a light signal directly in the optical domain, without converting it to an electrical signal.

How does an EDFA work?

The erbium-doped fiber is pumped with a laser at 980 nm or 1480 nm, causing a population inversion of the erbium ions. When a signal in the C-band (1530–1565 nm) passes through the fiber, it triggers stimulated emission, amplifying the signal proportionally to its intensity, at a relatively low level of introduced noise.

Applications

The EDFA is the standard amplifying element in long-haul DWDM systems, compensating transmission losses every 60–100 km without needing electrical signal regeneration, which significantly reduces the cost and complexity of the network.

Related terms

DWDM

Optical Q-factor

BER