报道了采用三镜腔结构的Ｃｒ∶ＬｉＳＡＦ激光器在低功率的氩离子单谱线激光泵浦下，连续光、自调Ｑ、自锁模和自调Ｑ－自锁模的运转特性。当泵浦功率为８６０ｍＷ时，在腔内不加任何调制器和可饱和吸收体，可实现自锁模运转，得到重复频率为１５０ＭＨｚ，脉冲宽度为５１ｆｓ，输出功率为４８ｍＷ的脉冲序列 The operation characteristics of continuous light, self-Q, self-mode-locked and self-Q-mode self-mode locked by Cr:LiSAF laser with three-cavity structure are reported. When the pump power is 860mW, without any modulator and saturable absorber in the cavity, self-mode-locked operation can be realized and a pulse sequence with a repetition frequency of 150MHz, a pulse width of 51fs and an output power of 48mW is obtained