研究了光学三稳态系统中的两种慢化现象。一种是发生在两类临界点附近的慢化现象（即所谓的临界慢化），计算出了它们的临界慢化指数。另一种是远离临界点的慢化现象，这是一种与不稳工作点有关的慢化现象。本文的讨论具有一定的普适性。

Two kinks of the slowing down in the optical tristability systems are studied. One is the critical slowing down at the edges of tristable region and the bifurcation, and their critical exponent is calculated; the other is the slowing down far from the critical point, which is concerned with the unstable steady points. The results show universal properties.