掺Er3+飞秒光纤放大器的特性研究

依据二能级速率方程和光传输方程,理论计算了Er3+光纤放大器中Er3+光纤的最佳长度Lc. 以全光纤飞秒激光器输出的孤子脉冲作为种子源,以理论值Lc作为实际采用的光纤长度,实验测量了Er3+光纤放大器在同向泵浦和反向泵浦下信号光的输出功率,得到同向泵浦的增益为20.0dB, 反向泵浦的增益为20.2 dB.同时测量了脉冲宽度随泵浦功率的变化,实验结果表明,随着泵浦功率的增大,输出光脉冲的宽度的压缩效应经历逐渐增强后逐渐减弱的过程.在同向泵浦方式下,可以得到更短的输出脉宽,其最短脉冲宽度为260 fs.

The Characters of Femtosecond Er3+ Doped Fiber Amplifier

Basing on two energy level rate equation and propag ation equation, the optimum fiber length L c of Er 3+ doped fiber amplifier was theoretically calculated. In our experiments, the seed source was generated by the femtosecond soliton pulse of a self-starting pulse mode-locked Er-doped fiber laser. The Er 3+ fiber length is selected according to L c. The amplified signal light power both with forward pumping and backward pumping was measured. The gain is 20.0 dB with forward pumping and 20.2 dB with backward pumping. It indicates that the pulse duration varied as the pumping power is increasing, and the shortest pulse duration is 260 fs with forward pumping.