Study Of The EYDFA In The Application Of Wavelength Division Multiplexing System

WDM (Wavelength Division Multiplexing) system that greatly improves thetransmission capacity can solve the problem of inadequate network bandwidth to meetthe growing demand for information transmission. Erbium-doped fiber amplifier(EDFA) as a key component in WDM systems has an positive effect on enhancing thegain and extending the transmission distance. However, with the increasing users innetwork, the demand for more longer transmission distance, the increasingtransmission channel and transmission code rate, EDFA gain spectrum is not flat sothat it will have very serious impact on WDM system.Double-clad Er-Yb co-doped fiber amplifier (EYDFA) that is an improvement ofEYFA, can not only overcome the pairs quenching phenomenon because of increasingEr ion concentration, but also increase the ion doping concentration, enhance pumpconversion efficiency, output power and obtain better gain flatness, to achieve ultra-long-distance transmission with reducing the use of relay devices and costs. This isconsistent with WDM system needs for ultra-high speed, large capacity and long-distance.This article describes the development of optical amplifiers in WDM systems, andalso introduces the level structure, rate equations, the basic composition andperformance of erbium ytterbium co-doped amplifier, and then focuses on the analysisof power conversion efficiency (PCE), amplified spontaneous emission (ASE), gainflatness and the nonlinear effect of high-power EYDFA in the WDM system under therate equations model, and also gives the corresponding simulation. Analysis shows that,PCE in backward pumping is best; forward-propagating ASE and the amplifier noisefigure in backward pumping is higher; Er-Yb co-doped fiber amplifier has good gainflatness under different pump power and improve the nonlinear effect.