Analysis For Amplified Spontaneous Emission In EDF Pumped By980nm Pulse Light

Because of its advantages of high gain, broadband, low noise, high efficiency, low connection loss and polarization independence, EDFA has a broader range of application compared with other optical amplifiers and takes a great role in modern fiber communication system. It is also a key device to achieve all optical transmission and communication. Traditionally EDFA is pumped by CW light. But it has been found that pulse light pumping has advantages of low energy consumption, less heat, taking maximum use of the power of pump light and has an ideal application prospect. Meanwhile ASE is one of the main factors that influence the operation of EDFA. Now there have been too many researches of ASE in the condition of CW light pumping. The influence that pulse pump light has on EDFA need to be studied.In this paper we studied ASE of EDF in the condition of pulse light pumping in theory by deducing rate equation of EDF. An approximate analytical solution of output ASE average power is achieved. Then we did experiments by changing pump light pulse width, pulse amplitude and its duty cycle, and research the influence on ASE output power. The experiment results show that ASE output power will increase when pulse width, pulse amplitude and duty circle increase. To meet the requirements of experiments, we designed980nm high speed pulse light LASER. The laser can provide CW light output and pulse light output, while pulse width, laser power and duty circle tunable. Pulse width can be as short as10ns. CW light power can reach180mW, and pulse laser peak power is160mW.