在基于半导体光放大器的激光器中,观察到了自锁模现象,得到了脉宽分别为30ns和50ns的重复频率分别为19.34MHz和9.67MHz的光脉冲。激光器采用环形腔结构,半导体光放大器为自锁模的关键器件,当其抽运电流为200mA时,调整偏振控制器开始出现自锁模脉冲。实验调试过程中,还观察到了重复频率的二分频现象,即激光器输出的光脉冲的重复频率是激光器基频的1/2。半导体光放大器的偏振旋转导致了输出激光功率的变化,出现了高功率和低功率脉冲交替出现的现象,即重复频率二分频现象。 In the semiconductor optical amplifier based lasers, the phenomenon of self-mode-locking was observed and the optical pulses with pulse repetition frequency of 19.34MHz and 9.67MHz with pulse widths of 30ns and 50ns respectively were obtained. The laser adopts a ring cavity structure, and the semiconductor optical amplifier is a key device for self-mode locking. When the pumping current is 200 mA, the polarization controller is adjusted to start the self-clamping mode pulse. In the course of experimental debugging, the two-way frequency of repetition frequency was also observed. That is, the repetition frequency of the laser pulse output was 1/2 of the fundamental frequency of the laser. Polarization rotation of the semiconductor optical amplifier results in a change in the output laser power, resulting in an alternating phenomenon of high-power and low-power pulses, that is, a repetition frequency of two.