考虑到垂直腔面发射激光器中的光子与载流子的纵向耦合, 在行波速率方程中引入了纵向耦合因子。 利用这个速率方程, 讨论了阈值电流与量子阱数目的关系, 计算结果表明光子与载流子的纵向耦合是不容忽视的。 给出了阈值电流表达式, 它表明纵向耦合因子越大, 阈值电流越低。

A longitudinal coupling factor is introduced into the rate equation of vertical cavity surface emitting lasers (VCSELs), taking the longitudinal coupling between photon and carrier into account. By using this modified equation, the relation between threshold current and number of quantun wells (QWs) is analyzed. The results show that the effect of longitudinal coupling between photon and carrier is not negligible. Furthermore, an expression for VCSEL′s threshold current Jth is given, which indicates that the bigger the longitudinal coupling factor is, the lower the threshold current is.