新型碲化锗铬可饱和吸收体的制备、表征及其在孤子锁模光纤激光中的应用研究

Ultra-fast passively mode-locked fiber lasers based on saturable absorbers have wide important applications in the fields of basic scientific research and engineering fields. Saturable absorbers with excellent nonlinear absorption properties have attracted more attention. In our project, based on a new two-dimensional ferromagnetic semiconductor Cr2Ge2Te6 as saturable absorber, we proposed a new demonstration for obtaining passively mode-locked Er-doped fiber laser. In detail, based on early theoretical simulations, the relationships between the nonlinear optical properties (third-order nonlinear coefficient, modulation depth, saturation intensity, damage threshold and unsaturable loss) and physical morphology and properties (thickness, morphology, crystal structure) of Cr2Ge2Te6 will be investigated. Additionally, the influence of the parameters of the prepared saturable absorber on the output characteristics of the mode-locked fiber laser also will be studied. Finally, by optimizing the parameters of the saturable absorber and the laser cavity, various kinds of solution mode-locked pulse operations will be observed. Our research results are of great significance in promoting the application of 2D materials in the field of ultra-fast optics, and providing a foundation for further research and application of 2D materials. In addition, It is of great significance to promote the applications of passive fiber mode-locked lasers.

基于新型二维可饱和吸收体的超快被动锁模光纤激光在基础科学研究及工业生产中具有广泛的应用，是当前国内外激光研究的热点。研发性能优异的新型可饱和吸收体材料是超快被动锁模研究领域的重要目标。本课题首次提出制备新型二维铁磁碲化锗铬(Cr2Ge2Te6)可饱和吸收体，研究Cr2Ge2Te6可饱和吸收体非线性光学性质（三阶非线性系数、调制深度、饱和光强、损伤阈值及非饱和损耗等）与其物理形态及特性（厚度、形貌、晶体结构等）的内在联系；研究Cr2Ge2Te6可饱和吸收体参数对传统孤子锁模光纤激光输出特性的影响；最后，通过优化可饱和吸收体参数及激光谐振腔参数等研究多形态的孤子锁模激光的输出特性及演化机理。相应研究结果将对推动新型铁磁半导体二维材料在超快光学领域的应用及新型锁模光纤激光的研究进展具有重要意义。

激光器的发明，引领着世界诸多领域的发展。光纤激光器凭借自身较低的成本，便于集成，优异的输出性能，占据了目前激光器行业的半壁江山。随着各研究领域以及市场对于光纤激光器的进一步需求，使得光纤激光器的研究进一步深入。超短脉冲以及大能量光纤激光器一直是研究的中心，进一步提升脉冲质量或者脉冲种类的研究具有一定的适用价值。本项目中介绍了采用不同工艺制备的新型碲化锗铬可饱和吸收体，并应用于光纤激光器，获得了不同性能的锁模脉冲，概括如下:.1.采用新型碲化锗铬Cr2Ge2Te6二维材料利用不同工艺制备成可饱和吸收体并对其进行表征实验，并且采用不同的结构将制备的二维Cr2Ge2Te6纳米片制备成可饱和吸收器件耦合进光纤激光器中。.2.采用紫外/可见/近红外分光光度计和双平衡检测系统测试基于Cr2Ge2Te6的可饱和吸收体器的光透过率和可饱和吸收特性。.3.探索在光纤激光器中利用二维Cr2Ge2Te6所制成可饱和吸收体器作为锁模器件时，多种孤子现象的演化，并且通过提高制备工艺水平和光纤激光器的参数精度，不断优化激光输出性能。