对一种结构新颖的自调Q掺铒光纤环形激光器的工作机理进行了研究。结果表明,该激光器中由光纤耦合器和半导体激光器芯片组成的反馈光路,依据光纤环中相向传输激光场相差的不同,对进入掺铒光纤的激光场进行选择反馈,在光纤环中激发幅度不断增强的光脉冲,引起掺铒光纤的瞬态增益饱和,实现激光器的自调Q。理论分析能较好地解释实验中观察到的现象。

The mechanism of a novel structure self-Q-switched erbium-doped fiber ring laser has been investigated. The results show, according to phase difference of counterpropagating light fields in a fiber loop, the optical feedback which is consisted of afiber coupler and LD chip can feedback light fields into the erbium-doped fiber selectively, and the laser can generate optical pulses with increasing amplitude. Optical pulses lead to transient gain saturation of the erbium-doped fiber, which will result in self-Q-switching in the laser. The theoretical analysis is in good agreement with the experiments.