Luo Zhengqian, Yang Runhua, Du Tuanjie, Ruan Qiujun, Li Weiwei, Chen Nan
Appl Opt. 2017 Aug 1;56(22):6103-6107. doi: 10.1364/AO.56.006103.
In this paper, we report the intermode beating mode-locking of a 2 μm Tm-doped fiber laser (TDFL) pumped by a 1565 nm continuous-wave multi-longitudinal-mode laser. Because strong intermode beating of the 1565 nm pump source induces the periodic modulation of 2 μm intracavity power, stable mode-locking of the TDFL is successfully established by precisely matching the 2 μm cavity frequency with the intermode-beating frequency of the 1565 nm pump source. The mode-locked laser, without requiring any specific mode-locking element, can stably emit the rectangular nanosecond pulses. The mode-locking operation at the center wavelength of 1980.35 nm has a >61 dB signal-to-noise ratio and a 34.496 MHz repetition rate. Although the preliminary results are not better than those of conventional mode-locking, intermode beating mode-locking in combination with rare-earth-doped fiber lasers could provide a promising and alternative solution for compact, low-cost, and high-performance pulsed laser sources.
在本文中，我们报道了由1565 nm连续波多纵模激光器泵浦的2μm掺铥光纤激光器（TDFL）的模间拍频锁模。由于1565 nm泵浦源的强模间拍频会引起2μm腔内功率的周期性调制，通过将2μm腔频率与1565 nm泵浦源的模间拍频精确匹配，成功实现了TDFL的稳定锁模。该锁模激光器无需任何特定的锁模元件，就能稳定地发射矩形纳秒脉冲。中心波长为1980.35 nm的锁模操作具有大于61 dB的信噪比和34.496 MHz的重复频率。尽管初步结果并不优于传统锁模，但模间拍频锁模与掺稀土光纤激光器相结合，可为紧凑、低成本和高性能脉冲激光源提供一种有前景的替代解决方案。
