采用基于速率方程的离散算法，对双包层Er³⁺／Yb³⁺共掺光纤激光器增益介质在不同位置的动态特性进行了分析。研究了增益介质在不同位置上的能级粒子数、激光功率随时间的变化。结果表明：增益介质在不同位置振荡达到稳态前上能级粒子数随时间的变化是不同的，并呈现出了不同的变化特点；不同位置处振荡开始时的最大峰值功率与达到稳态时的功率也不同；不同位置开始振荡的时间相同，达到稳态的时间也基本相同。对这一算法的稳态结果同简化速率方程的稳态分析值进行了对比，显示了泵浦功率较大且光纤长度较长时两者所具有的差异。

Based on the discrete algorithm of rate equations,an analysis of the dynamic behavior of Er³⁺ /Yb³⁺ co-doped double-clad fiber laser at the different position of fiber was achieved. The changes of both population in ⁴I_13/2 and ²F_5/2 levels and laser power were studied. The results show that the changes of the population have different characteristics at different positions,and that both the maximum peak power of relaxation oscillation and the steady-state power are different at different positions. This study further shows that the time of both relaxation oscillation starting and steady state reached is almost same. The comparison is done between the steady-state results of discrete and simplified algorithm for rate equations,which shows slightly difference when pump power is higher and fiber length is longer.