高重频大脉冲能量激光在基础科学研究以及通信、探测、材料加工等应用领域具有重要价值。报道了溶液法制备的过渡金属二硫化物NbSe₂纳米颗粒材料的线性和非线性光学特性，并利用其2 μm波段可饱和吸收特性对掺铥光纤激光器进行被动调制实现了2 μm锁模激光输出。线性测量发现NbSe₂纳米材料的光学吸收覆盖近红外到近中红外波段且随波长增加而降低；非线性光学测量显示NbSe₂纳米材料在2 μm波段的调制深度为6.5%、饱和强度为19 MW·cm^?2。然后我们把NbSe₂纳米材料转移到金镜上制作成可饱和吸收器件，并对掺铥光纤激光器进行调制得到2 μm耗散孤子谐波锁模激光，单脉冲能量为3.36 nJ，脉冲宽度为1.48 ns，重复频率为50.66 MHz。激光光谱的中心波长为1 910.8 nm，光谱宽度为5.8 nm。首次在2 μm光纤激光器中采用NbSe₂纳米颗粒实现耗散孤子锁模，证明了NbSe₂纳米材料在2 μm波段的非线性光学调制能力，结合纳米颗粒的可集成特性，溶液法制备的NbSe₂纳米材料有望成为一种新型的宽谱非线性光电调制材料/器件。

High-repetition-rate laser pulses with large pulse energies have great application potential in various areas including telecommunications, sensing, material processing, etc. Here, we report the linear and nonlinear optical properties of solution-based transition-metal dichalcogenide NbSe₂ nanoparticles, and at the same time its application to mode-locked 2 μm fiber laser. The linear absorption of the NbSe₂ nanoparticles covers the near-infrared to the near mid-infrared regions, and decreases with increasing wavelength, showing a broadband operation potential. Nonlinear absorption measurement of the NbSe₂ nanoparticle gives a modulation depth of 6.5% and saturable intensity of 19 MW·cm^?2 at the wavelength of about 2 μm. The the NbSe₂ nanoparticles were transferred onto a gold mirror to fabricate a saturable absorber, with which a mode-locked thulium fiber laser was constructed and harmonic mode-locking was achieved. The mode-locked laser provides pulse energy of 3.36 nJ, pulse duration of 1.48 ns and repetition rate of 50.66 MHz. The laser wavelength is centered at 1 910.8 nm with a spectral bandwidth of 5.8 nm. The realization of dissipative-soliton mode-locking in the 2 μm fiber laser with NbSe₂ nanoparticles proves that NbSe₂ nanoparticles are good modulators for pulse generation in the 2 μm spectral region, and the integratable solution based nanoparticles hvae the potential of being new broadband nonlinear light modulators.