The main difference: the amplification mechanism is different.
EDFA uses the principle of stimulated radiation of EDF fiber to amplify the optical signal, and Raman amplification uses the Raman effect to realize energy conversion and amplify the optical signal.
In addition, the edfa amplification bandwidth is limited (around 1550nm), and Raman amplification can theoretically amplify all bands.
The medium of Raman amplification adopts ordinary transmission fiber and does not require additional gain medium. According to different operating distances, it is divided into distributed amplification (the amplification effect occurs within tens of kilometers of fiber) and centralized amplification (the amplification effect occurs within a few kilometers). fiber optic).
Raman amplification can achieve low noise amplification, which is better than EDFA, but the amplification gain is lower than EDFA (about 3 ~ 15db), and requires higher pump light (watt level)
Both EDFA and Raman amplifiers have high gain, low noise figure and high output power. The following table lists the differences between the two types:
