狄拉克材料表面等离激元的非线性吸收特性研究

Graphene, as a typical Representative of Dirac material, can exhibit broadband nonlinear optical absorption effects, which has many applications in visible and infrared laser field. These two key issues will be resolved that is the excited SPPs of Dirac material in optical frequency band and the flexibly regulated nonlinear absorption. Moreover, the coupling structures of prism, grating and near field for exciting SPPs will be studied. Then, the nonlinear absorption characteristics and regulation of Dirac materials will be analyzed based on applied electric and magnetic field techniques and metasurface microstructure. That will be experimental investigated based on Z-scan system. Then, a new coupling structure for high efficiency excitation of SPPs is obtained. The nonlinear absorption theoretical models are improved and correspondence between the various structure parameters and nonlinear absorption properties is revealed. These results not only offer a new way to development of new photonic devices, but also expand the application of Dirac material in nanophotonics technology.

以石墨烯为代表的狄拉克材料，具有宽频带的非线性吸收特性的优点，被广泛应用于可见光和红外激光技术领域。本项目将针对狄拉克材料在光频段激发SPPs和灵活调控SPPs的非线性吸收两个关键问题，主要研究激发SPPs的棱镜、光栅和近场三种耦合结构，外部电磁场和超表面微结构调控非线性吸收的机制以及基于Z扫描系统进行实验验证。以期获得高效激发SPPs的新型耦合结构，完善调控SPPs非线性吸收的理论模型，得出非线性吸收调控的量化指标。本项目的研究结果将为发展新型光子器件提供新途径，进一步拓展狄拉克材料在纳米光子学领域中的应用。

表面等离激元（Surface Plasmon Polaritions, SPPs）是存在于导体与电介质分界面的集体电荷振荡，可实现纳米尺度的光场调控，在微纳器件、近场成像和光传感等领域展示出良好的应用前景。本项目研究狄拉克材料微结构实现高效激发SPPs的机制，拓展纳米光调控手段，应用于光延时、横移和传感器件的设计。项目执行期间，开展了以下工作：1.SPPs的光学响应特性方面，研究了狄拉克材料微结构的反射、透射、吸收、色散关系、传播模式、导波等光学特性和优化激发SPPs的多种耦合结构参数。2.SPPs光延时方面，分别研究了石墨烯-氮化硼和石墨烯-光子晶体异质结构的反射群延时调控，实现了红外波段和光通信波段的延时值有效增强，设计了一种可调谐的光延时器新方案。3.SPPs光横移方面，基于Otto耦合结构，实现了石墨烯-介质层状结构的SPPs的有效激发，实现古斯汉欣横移的增强，横移值可正负调控。4.SPPs光传感方面，设计了一种石墨烯-氮化硼-双金属的高灵敏度折射率传感器，可获得2.02×10^5 λ/RIU灵敏度，有效增大了传统金属传感器的探测范围。以上结果发表科研论文5篇，包括SCI论文3篇，EI会议论文1篇，授权发明专利3项，实用新型专利1项和软件著作权4项，毕业硕士生5人。