The main function of the EDFA optical amplification subsystem is to compensate the signal’s optical power in the transmission link, which can finally extend the optical signal transmission distance. It can be divided into OBA, OLA and OPA based on the application scene. BA is usually used at the transmitting end to boost the output optical power of the system. LA is usually used at the repeater section to compensate the power loss of the line. PA is usually used at the receiving end of the system to improve the input optical power. The EDFA can amplify all the input optical signals by using the erbium-doped fiber as the gain medium and using the 980nm or 1480nm pump laser as the pump source with one-stage or two-stage amplification.

It’s one of the most indispensable and important part of the DWDM system, high speed transmission system and all optical network in the future.