Optical commu bium Doped Fiber Amplifiers 12021/2/19 Wavelength selective Erbium doped npu direction al coupler fiber Output 155pm 155um Pump:1.48μm(98onm) 1.48um EDFA Advantages Cavers the important 1550 nm(1528-1605)band with low cross talk between WDM channals Relatively simple structure (although practcal EDFAs have several stages and additional components for gain flattening and output isolation etc. high gain Semiconductor pump lasers are available Can be directhy spliced to sMF even though the core is smaller typica lly EDFA Challenges Gain flattening Some cross talk(saturation Cannot be extended to other wavelength bands Raman (flexible spectrum) amplifiers might become the preferred technology
1-1 Copyright Wang Yan 2021/2/19 Optical fiber communications 第二节 Erbium Doped Fiber Amplifiers