非线性偏振旋转锁模光纤激光器数值模型(英文)

Numerical model for nonlinear polarization rotation mode-locked fiber laser

利用二能级Giles模型来计算掺铒光纤增益,并通过琼斯矩阵描述偏振控制器,提出了一种基于非线性薛定谔方程的非线性偏振旋转锁模光纤激光器的数值模型。该模型具有物理意义更加清晰、便于分析泵浦功率对锁模影响的优点。采用1.0 m长的掺铒光纤、5.8 m长的单模光纤和85:15的输出耦合器,当泵浦功率为25 mW时数值计算得到均方根宽度为0.30 ps的超短脉冲。研究了泵浦功率对锁模脉冲波形和光谱的影响,并讨论了泵浦功率与掺铒光纤中增益分布的关系。通过实验得到了锁模脉冲,其光谱形状与仿真得到的结果相似。测量了不同泵浦功率下脉冲的平均功率,变化趋势也与理论值吻合。

Employing nonlinear Schrodinger equations,, a numerical model for nonlinear polarization rotation mode-locked fiber laser was put forward. Jones matrix was used to describe polarization controllers while two-level Giles model was used to calculate the gain. This numerical model has clear physical significance and is conducive to analyze the influence of pump power. With 1.0 m-long erbium doped fiber, 5.8m-long single mode fiber and 85：15 output coupler, ultrashort pulse with the root-mean- square width of 0.30 ps was derived when pump power was 25 roW. The influence of pump power on the waveform and optical spectrum of mode-locked pulse was investigated, and the relation between pump power and gain distribution in erbium doped fiber was discussed. Mode-locked pulse was derived in experiment, whose optical spectrum was similar with numerical result in shape. The average power of pulse was measured and the variation trend is in line with theoretical result.