黑磷双光子激发的非线性吸收特性研究

Black phosphorus (BP) has attracted much attention owing to the specific 2D geometry and quantum size effect, tunable direct bandgap ranging from 0.3 eV to 2 eV, high carrier mobility and remarkable in-plane anisotropic electrical, optical and phonon properties, and will have a great application prospect in the optoelectronic field. However, the nonlinear absorption (NLA) property study of BP mainly focus on saturable absorption at present. The rules of two-photon absorption (TPA) variation with the layer number, excitation laser polarization, pulse energy, in-plane anisotropic, etc. are still not clear. The absence of intensive study of NLA property-structure relationship will seriously restrict its application. The project aims to study the infrared TPA property of layered BP by experiment and theoretical modulation combination. We will analyze the influence of layer number, excitation laser polarization, pulse energy and in-plane anisotropic on the TPA performance, understand the physical mechanism of TPA and modulation characteristics of BP, to realize breakthrough of performance of black phosphorus based optical modulators and broadband laser protection devices.

黑磷独特的二维层状结构和量子限制效应，随层数可调的超宽直接带隙、高载流子迁移率和光电特性的各向异性，使其在光电子学领域具有巨大地应用前景。然而，目前关于黑磷非线性吸收特性的报道主要集中在饱和吸收，双光子吸收特性及其随层数、偏振、脉冲能量的变化规律，面内各向异性对双光子吸收效应的影响及物理机理尚不清楚。缺乏精确的非线性光学构性关系研究制约着黑磷在光电子学领域的发展。本项目将在前期工作基础上，实验与理论相结合深入研究黑磷在红外波段的双光子吸收物理过程，通过分析黑磷双光子吸收的层数依赖、偏振依赖、脉冲能量依赖和各向异性性质，掌握黑磷非线性吸收的物理机理和调制规律，为开发基于黑磷双光子吸收特性的超宽带光电调制器件和激光防护器件奠定良好的物理基础。

针对黑磷等二维纳米材料非线性光学特性的基础研究对开发光限幅器、饱和吸收器等意义非常重大，该项目在前期工作基础上实验与理论相结合深入研究了该类材料的非线性吸收、非线性折射、超快动力学特性，揭示了其三阶非线性物理机制，提出并验证了非线性光学特性的调控策略，发展了相应的光限幅器等调制器件和技术。重要结果如下：1）研究了共价修饰黑磷材料的光限幅特性，开发了激光防护器件。2）详细研究了非层状半导体PtS和层状材料PtSe2的非线性光学特性和超快载流子动力学特性。3）详细研究了微生物合成Te纳米材料的非线性光学特性。4）详细研究了MoS2中层数依赖的双光子吸收特性。.受本项目资助，共发表SCI论文10篇，包含：ACS Nano、Nature Communications、Laser & Photonics Reviews、ACS Photonics、Journal of Materials Chemistry C、Photonics Research、Optics Express、Polymer Chemistry、Optical Materials Express、ACS Applied Nano Materials各1篇。国际国内会议口头报告5人次，其中境外举办会议3人次。项目负责人入选中科院青年创新促进会会员（2019）；培养研究生6人，其中已毕业博士2人，已毕业硕士1人，获“博士研究生国家奖学金”1人次、“朱李月华优秀博士生奖学金”1人次、上海市优秀毕业生1人次。