Optical fiber amplifier (OpticalFiberAmplifier, abbreviated as OFA) refers to a new type of all-optical amplifier used in optical fiber communication lines to achieve signal amplification. According to its position and role in the optical fiber line, it is generally divided into three types: relay amplification, preamplification and power amplification. Compared with traditional semiconductor laser amplifiers (SOA), OFA does not need to go through complex processes such as photoelectric conversion, electro-optical conversion, and signal regeneration. It can directly amplify signals with all-optical amplification. It has good "transparency" and is especially suitable for long-distance applications. Relay amplification for optical communications. It can be said that OFA has laid a technical foundation for the realization of all-optical communications.
