EDFA is an Erbium-Doped optical Fiber Amplifier, which is an active optical device that amplifies signal light. The main function is to perform power compensation for the signal light in the transmission link.
Why use EDFA: The transmission loss and dispersion of the optical fiber limit the transmission distance of the optical signal. Therefore, during long-distance transmission, a repeater station (optical amplifier) needs to be added every certain distance. The optical amplifier completes the signal amplification and regeneration. to ensure transmission quality.
The production process of EDFA is that erbium ions are doped in the core material silica of the optical fiber, and a separate pump light source is provided externally, so that the erbium ions in the core are "stimulated" by the pump light to generate energy levels. The EDFA optical amplifier is essentially the same as the laser. The light amplified by the laser is the light generated by the gain material in the resonator, while the amplifier amplifies the light input from the outside.
EDFA can also be connected in series for cascade amplification. because the EDFA is also an optical fiber, the connection with the optical fiber is relatively easy, that is, the coupling efficiency is high.
The advantages of EDFA are low operating wavelength loss, wide frequency bandwidth, high gain and low noise.
The disadvantage of EDFA is that it can only amplify light in the 1550nm band.
