Opt Lett. 2018 Nov 1;43(21):5315-5318. doi: 10.1364/OL.43.005315.
We experimentally demonstrated an all-optical tunable sub-kHz single-mode fiber laser based on an ultrahigh-quality (Q)-factor hybrid microbottle resonator. The wavelength tunability is a very important function for fiber lasers, and the all-optical tuning method has rarely been proposed. Here, we use the iron-oxide-nanoparticle-coated silica microbottle resonator with a Q factor of 1.8×10 as the feedback element of the fiber ring laser and suppress the higher-order modes of the microresonator to achieve single-mode lasing with a linewidth of ∼500 Hz and a signal-to-noise ratio of 49 dB. Iron oxide nanoparticles are coated on the tapered area of the microbottle resonator and the control light is fed through the axial direction of the microbottle. The lasing wavelength of the fiber laser can be all-optically and linearly tuned with a range of 2.7 nm due to the strong photothermal effect of iron oxide nanoparticles. With such an excellent tunability and a narrow linewidth, this single-mode fiber laser has great potential in applications, such as optical spectroscopy, sensing, and signal processing.
我们实验演示了一种基于超高 Q 因子（Q 因子）混合微球谐振器的全光可调谐亚千赫兹单模光纤激光器。波长可调谐性对于光纤激光器来说是一个非常重要的功能，而全光调谐方法很少被提出。在这里，我们使用铁氧化物纳米粒子涂覆的 Q 因子为 1.8×10 的二氧化硅微球谐振器作为光纤环形激光器的反馈元件，并抑制微谐振器的高阶模式，从而实现线宽约为 500 Hz，信噪比为 49 dB 的单模激光。铁氧化物纳米粒子涂覆在微球谐振器的锥形区域上，控制光通过微球的轴向输入。由于铁氧化物纳米粒子的强光热效应，光纤激光器的激光波长可以通过全光和线性调谐，调谐范围为 2.7nm。由于其出色的可调谐性和窄线宽，这种单模光纤激光器在光学光谱学、传感和信号处理等应用中具有很大的潜力。
