对自锁模掺钛宝石激光器的原理作了较详细的描述，指出克尔透镜效应是形成自锁模的主要原因。在自聚焦理论基础上，从无象散近似出发.推导出钛宝石棒的非线性矩阵，由此得出钛宝石激光器的谐振腔设计方法，并且讨论了谐振腔稳定性对自锁模的影响、软光阑与硬光间的不同之处以及腔内的群速度色散补偿。最后，将计算结果与实验作了比较.两者符合得很好。

A theory of self-mode-locking of Ti:sapphire laser is described. A nonlinearABCD matrix,derived from the aberrationless theory of self-focusing, is introduced to treatthe propagation of Gaussian beams in materials with Kerr nonlinearity,showing that selffocusing in the laser rod leads to modification of the Gaussian beam parameters either in therod or on the resonator mirrors.An optimum resonator design for Kerr-lens-mode-lockingwith(or without) hard-aperture is given.A theoretical prediction is confirmed by the experimental result.