Abstract The uniformly sized two-dimensional (2D) bismuthene quantum dots (BiQDs) were fabricated through the liquid-phase exfoliation (LPE) route and characterized comprehensively. By transferring the BiQDs onto a quartz substrate, BiQDs saturable absorber (SA) was prepared and applied in a Tm:YLF bulk laser. To get the best output performance of passive Q-switching (PQS) laser with BiQDs-SA, three output couplers with different transmittance were applied in laser implementation. The stable solid-state 2 μm laser was obtained, generating a maximum peak power of 8.1 W and shortest pulse width of 440 ns with the T = 5% output coupler. To the best of our knowledge, it is the first demonstration of BiQDs-SA for Q-switching operation around 2 μm, implying that the BiQDs-SA can be considered as a promising optical modulator for the mid-infrared (MIR) pulses producing.

中文翻译：

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用于 2 μm 中红外激光器的基于铋量子点的光学调制器

摘要 通过液相剥离 (LPE) 路线制备了均匀尺寸的二维 (2D) 铋量子点 (BiQD) 并对其进行了综合表征。通过将 BiQDs 转移到石英衬底上，制备了 BiQDs 可饱和吸收体 (SA) 并将其应用于 Tm:YLF 体激光器。为了获得具有 BiQDs-SA 的无源调 Q (PQS) 激光器的最佳输出性能，在激光器实现中应用了三个具有不同透射率的输出耦合器。获得了稳定的 2 μm 固态激光器，在 T = 5% 输出耦合器的情况下，产生的最大峰值功率为 8.1 W，最短脉冲宽度为 440 ns。据我们所知，这是 BiQDs-SA 用于 2 μm 左右 Q 开关操作的首次演示，