We experimentally demonstrated a novel repetition rate adjustable SBS-based Q-switched fiber laser. An inserted Fabry-Perot interferometer formed by two non-contact end faces of two FC/PC fiber connectors was inserted to help the system stabilize the random output of SBS-based Q-switching. By mechanically fine-tuning the length of the inserted Fabry-Perot interferometer, a linear and continuous repetition rate adjustment under a fixed pump power was achieved. This method paves a new way for the indirect control of repetition rate in SBS-based Q-switched fiber lasers. It is also found out that higher pump power allows wider adjustment range. At 600 mW pumping which is highest pump power of the source, the repetition rate almost tripled from 11.22 kHz to 32.06 kHz only by varying the length of FP cavity in less than 3 μm. In the meantime, the variation of pulse width, output power and single pulse energy were recorded and analyzed under different fixed pump powers. Although the adjusting range of repetition rate is not very wide but the tuning of repetition rate due to such a small length changing is unique and valuable. This original repetition rate control technique has great potential in areas like environment sensing and material detections.

中文翻译：

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一种新型重复频率可调的基于SBS的调Q光纤激光器

我们通过实验证明了一种新颖的重复率可调 SBS 调 Q 光纤激光器。插入由两个 FC/PC 光纤连接器的两个非接触端面形成的插入式法布里-珀罗干涉仪，以帮助系统稳定基于 SBS 的 Q 开关的随机输出。通过机械微调插入的法布里-珀罗干涉仪的长度，在固定泵浦功率下实现了线性和连续重复率调整。该方法为基于SBS的调Q光纤激光器重复率的间接控制开辟了一条新途径。还发现更高的泵浦功率允许更宽的调节范围。在 600 mW 的泵浦功率（源的最高泵浦功率）下，仅通过将 FP 腔的长度改变小于 3 μm，重复率几乎从 11.22 kHz 增加到 32.06 kHz。同时，记录分析了不同固定泵浦功率下脉冲宽度、输出功率和单脉冲能量的变化。虽然重复率的调整范围不是很广，但由于长度变化如此之小而对重复率的调整是独一无二且有价值的。这种独创的重复率控制技术在环境传感和材料检测等领域具有巨大潜力。