Design of a gain flattened doped fiber amplifier with stabilized power output for WDM transmissions

The gain spectrum of an Erbium Doped Fiber Amplifier (EDFA) has a peak centered at 1532nm and a broad peak with relatively low gain centered at 1550nm. In many applications like soliton based systems which makes use of EDFA repeaters and Dense Wavelength Division Multiplexing (DWDM) systems where EDFA is used for amplifying a large number of wavelengths, gain fluctuations in EDFA has to be confined within specified limits over a wide span of wavelengths. Many methods of gain stabilization in EDFA has already been proposed in the recent past. In our work, we propose a novel method for gain contouring and output power stabilization in Erbium Doped Fiber Amplifiers. The amplifier with gain control is designed and simulated. The flattening of gain spectrum of EDFA is achieved by photonic switching using Optical Add Drop Multiplexers (OADM) and Fiber Bragg Gratings (FBG). The stabilization of gain and output power of EDFA is also experimentally verified. In the proposed feedforward technique, the output power stabilization is achieved by proper selection of modulator parameters.