讨论了慢恢复饱和吸收体的被动调Q过程。在合理简化被动调Q速率方程组的基础上，得到了能反映激发态吸收效应的慢恢复饱和吸收体被动调Q的判据，以及调Q脉冲的峰值功率、脉冲能量、脉冲宽度和能量利用率等调Q重要参量的解析表达式。结果具有一定的普遍性，有助于这类被动调Q激光器的优化设计。

The behavior of passive Q-switching with a slow saturable absorber is analyzed. From the simplified rate equations for passive Q switching, the criteria for passive Q-switching using a saturable long recovery time and excited state absorption, and the analytical formulas for the peak power, pulse energy, pulse width and energy extraction efficiency are derived. The general results have applications in the optimal design of such passive Q-switched lasers.