针对研究增益饱和时，现有的垂直腔半导体光放大器(VCSOA)速率方程模型在确定输入信号的功率注入因子方面存在难题，根据法布里－珀罗腔边界条件，从行波方程和与位置相关的载流子方程出发，引入随轴向位置发生变化的增益增长因子刻画微腔内的驻波效应，构建出VCSOA的增益模型。利用该模型通过求方程的自洽得到了腔内载流子、光子的分布，并分析了反射增益，其结果与已报道的理论及实验基本一致。

Considering the fact that power injection factor of the input signal is hard to evaluate when gain saturation is analyzed with existing rate equation models of vertical cavity semiconductor optical amplifier(VCSOA)according to the boundary condition of Fabry-Perot resonator,a gain model of VCSOA is established by using traveling-wave equation and position dependent carrier equation and employing gain enhancement factor which varies with axial position to describe the standing wave effect in a micro-cavity. After finding the self-consistent solution of equations based on the model,the distributions of carrier and photon in cavity are presented. Meanwhile,the reflection gain is investigated and agrees with the theoretical and experimental data.