2μm波段全固态、高峰值功率、可调重频（kHz）超短脉冲在医疗、非线性光学、激光加工等领域具有极大的应用价值。但单损耗调制锁模技术无法兼顾脉宽压缩和重复频率调节，激光峰值功率难以提升。基于主动开关和被动可饱和吸收体的双损耗调制技术同时具备超短脉宽、可调重复频率和高稳定性的特点，可使脉冲峰值功率显著提升。在此方案中，2μm 波段适用的可饱和吸收材料的选择至关重要。本项目拟选取黑磷（BP）和二硫化铼（ReS2），采用化学气相沉积（CVD）法构建异质结结构，制备高性能可饱和吸收元件。理论上，从材料的电子能带结构入手，结合2μm波段被动锁模动力学研究，探究异质结的非线性吸收机理；实验上，制备BP/ReS2异质结，并基于主被动双损耗调制技术，利用RTP（RbTiOPO4晶体）电光开关，探究2μm波段高峰值功率可调频锁模脉冲激光特性，为中红外波段激光领域的发展和应用提供有力的理论依据和全新的技术路径。

2μm all-solid-state ultrashort pulse lasers with high peak power and adjustable repetition rate (kHz) have wide applications in the fields of biological medicine, nonlinear optics, material processing and so on. However, by using single-loss modulation technologies of mode-locking, it is difficult to achieve ultrashort pulse width and adjustable repetition rate at the same time, resulting in a low peak power. The dual-loss modulation laser technology based on the active Q-switching and passive mode-locking of saturable absorbers can output ultrashort pulse with adjustable repetition rate (kHz) and high peak power. But in this technical scheme, it is essential to select suitable saturable absorbers in 2μm. In this item, black phosphorus (BP) and rhenium disulfide (ReS2) are chosen to construct heterojunction structure by the method of chemical vapor deposition (CVD) and saturable absorbers with high performance are prepared. In theory，combined with the study of electronic band structure and passive mode-locking mechanism in 2μm, the nonlinear saturable absorption mechanism of BP/ReS2 heterojunction will be investigated. Experimentally, by using the active and passive dual-loss modulation technology, based on the preparation of BP/ReS2 heterojunctions, and combined with RTP (RbTiOPO4) electro-optic modulator, the characteristics of the 2 μm mode-locking pulse laser with adjustable pulse repetition rate and high peak power will be investigated, which can provide a strong theoretical basis and a new technical path for the development and application of the mid-infrared band lasers.