Lu Bingbing, Zou Chuanhang, Huang Qianqian, Huang Zinan, AlAraimi Mohammed, Mou Chengbo, Luo Zhichao, Rozhin Aleksey
Appl Opt. 2020 Mar 20;59(9):2709-2714. doi: 10.1364/AO.387843.
We demonstrated a continuously wavelength-tunable bidirectional passively $ Q $Q-switched fiber laser based on a single-walled carbon nanotube saturable absorber and a bandpass filter (BPF). By tuning the commercial BPF, the $ Q $Q-switched pulse can be obtained in the same cavity at the same pump power in clockwise (CW) and counter-clockwise (CCW) directions. The central wavelength can be continuously tuned from 1520.88 to 1568.56 nm in the CW direction, and from 1520.96 to 1568.64 nm in the CCW direction. A wide tuning range of 48 nm is achieved for two directions in the passively $ Q $Q-switched fiber laser. During the tuning process of the fiber laser, the output pulses with the same central lasing wavelength can be obtained in both oscillation directions owing to the BPF. By increasing the pump power from 130 to 350 mW, the cavity delivers a $ Q $Q-switched pulse with the central wavelength of 1560 nm whose repetition rate changes from 9.64 to 59.18 kHz for the CW direction. In the CCW direction, the repetition rate of the $ Q $Q-switched pulse changes from 10.26 to 61.03 kHz. To the best of our knowledge, it is the first time that continuous wavelength-tunable passively $ Q $Q-switched pulses have been achieved in a bidirectional erbium-doped fiber laser.
我们展示了一种基于单壁碳纳米管可饱和吸收体和带通滤波器（BPF）的连续波长可调谐双向被动调Q光纤激光器。通过调谐商用BPF，在相同腔内以相同泵浦功率可在顺时针（CW）和逆时针（CCW）方向获得调Q脉冲。中心波长在CW方向可从1520.88连续调谐至1568.56 nm，在CCW方向可从1520.96连续调谐至1568.64 nm。在被动调Q光纤激光器中，两个方向实现了48 nm的宽调谐范围。在光纤激光器的调谐过程中，由于BPF，在两个振荡方向均可获得具有相同中心激射波长的输出脉冲。通过将泵浦功率从130 mW增加到350 mW，腔内输出中心波长为1560 nm的调Q脉冲，其重复频率在CW方向从9.64 kHz变化到59.18 kHz。在CCW方向，调Q脉冲的重复频率从10.26 kHz变化到61.03 kHz。据我们所知，这是首次在双向掺铒光纤激光器中实现连续波长可调谐被动调Q脉冲。
