掺钛蓝宝石自锁模激光器中产生自锁模的主要因素是自振幅调制（ＳＡＭ）、自相位调制（ＳＰＭ）和群速度色散（ＧＶＤ）．本文详细地分析了三要素在锁模脉冲形成的不同阶段所起的作用，指出在整个过程中自振幅调制对脉宽压缩起主要作用，而引入的适量负群速度色散在后期对ＳＰＭ效应与正ＧＶＤ起补偿作用，可获得最窄脉冲．最后，讨论了形成不稳定锁模脉冲的可能性． The main factors of self-mode-locking in Ti: sapphire self-mode-locked lasers are SAM, SPM and GVD. In this paper, the role of the three elements in the different phases of mode-locked pulse formation is analyzed in detail. It is pointed out that the self-amplitude modulation plays a major role in the pulse width compression during the whole process, while the introduction of the appropriate amount of negative group velocity dispersion affects the SPM effect and Positive GVD play a compensatory role, can get the narrowest pulse. Finally, the possibility of forming unstable mode-locked pulses is discussed.