基于层状黑磷可饱和吸收体的高能量、宽调谐、超短耗散孤子锁模光纤激光器

High energy, wide-tunable, ultrashort laser has been widely used in various fields of people's lives, such as scientific research, industry, defense, environment, energy, communication and so on. One of the key devices of generation of high-energy, wide-tunable, ultrashort dissipative soliton pulse is the saturable absorber. The two-dimensional material, just like graphene, can be used to prepare an efficient saturable absorber because of excellent saturable absorption, and brings opportunities of passively mode-locked ultrashort laser. With respect to the two-dimensional materials of graphene, topological insulator, molybdenum disulfide, a novel two-dimensional material of black phosphorus reported recently has unique photoelectric characteristics, such as the thickness-dependent direct band gap, anisotropy absorption and broadband saturable absorption. The black phosphorus will be a better broadband saturable absorber, which may be widely applied in high-energy, wide-tunable, dissipative soliton ultrashort laser. Therefore, this project researches and analyzes of nonlinear optical properties of the layered black phosphorus, reveals the relationships and mechanisms between the macroscopic properties and microscopic structures of the layered black phosphorus; theoretically analyzes the internal relations between the macroscopic properties of layered black phosphorus and frequency-time-domain characteristics of mode-locking dissipative soliton pulse; experimentally realizes the high-energy, wide-tunable, ultrashort dissipative soliton fiber laser mode-locked by layered black phosphorus.

高能量、宽调谐、超短激光已经广泛应用在科研、工业、国防、环境、能源、通讯等与人们生活息息相关的领域。作为产生高能量、宽调谐、超短耗散孤子激光脉冲的核心器件之一是可饱和吸收体。以石墨烯为代表的二维原子材料具有优良的饱和吸收特性，可以被用来制备成高效可饱和吸收体，并为被动锁模激光器带来蓬勃发展。相对于石墨烯、拓扑绝缘体、二硫化钼等二维材料，最近报道的新型二维材料黑磷具有独特的光电特征，如与层数相关的直接带隙、各项异性的光吸收、宽带可饱和吸收等。这预示着黑磷是一种更优秀的宽带可饱和吸收材料，将会在宽调谐、高能量、超短耗散孤子激光中产生重要的应用。鉴于此，本项目研究和分析层状黑磷的宽带非线性光学性能，揭示层状黑磷的宏观性能与微观结构之间的关系和机制；理论分析层状黑磷的宏观性能与耗散孤子锁模脉冲时域频域性质的内在关系；实验实现层状黑磷锁模的宽调谐、大能量、超短耗散孤子锁模激光。

高能量、宽调谐、超短激光已经广泛应用在科研、工业、国防、环境、能源、通讯等与人们生活息息相关的领域。本项目主要是研究二维材料黑磷可饱和吸收的高能量耗散孤子光纤激光器。首先，我们制备高质量的层状黑磷样品和二维材料黑磷可饱和吸收体。同时测量黑磷可饱和吸收体的非线性光学特性。然后，编写基于黑磷可饱和吸收体的耗散孤子光纤激光器程序；通过数值模拟，我们得到偏振锁定矢量孤子和偏振旋转锁定矢量孤子两种锁模状态。第三、基于黑磷可饱和吸收体锁模的全正色散掺镱光纤激光器，实验得到了大啁啾、高能量超短脉冲。通过改变可饱和吸收体的调制深度，得到Q调制的锁模态。最后，在黑磷可饱和吸收体锁模的正色散掺铒光纤激光器中，我们得到耗散孤子超短脉冲。改变黑磷可饱和吸收体的调制深度和饱和光强，实验得到高能量啁啾孤子晶体。在项目实施期间，发表SCI论文2篇；申请发明专利1项，目前该专利已经授权；参加学术研讨会2人次。研究结果表明黑磷可饱和吸收体在宽调谐、高能量、超短耗散孤子激光中产生重要的应用。