石墨烯/二维黑磷耦合的等离激元调控机理研究

The burgeoning two-dimensional (2D) layered materials and heterostructures offer a new platform for the study of micro-nano photonics devices. In this project, we will investigate systemically the surface plasmonic coupling mechanism of graphene coupled with 2D black phosphorus and the corresponding property modulation, both theoretically and numerically. We show similarities and differences in propagation constants of surface plasmon waves supported by graphene and 2D black phosphorus, respectively. We illuminate the critical condition of effective electromagnetic coupling between graphene and 2D black phosphorus, and present the redistribution of power in the coupling area, thereby realizing the controlled propagation of surface plasmon waves between graphene and 2D black phosphorus and obtaining the mode conversion. We demonstrate the effect of the introduction of anisotropic black phosphorus on the propagation character and the modulation dimension of graphene plasmons under the condition of effective coupling between them. We study the near-field and far-field coupling responses between black phosphorus ribbons with different lattice directions, and further reveal the physical mechanism of the splitting and engineering of Fano lineshapes induced by the near-field coupling between surface plasmon polaritons (SPPs) in monolayer graphene and excited double-continuous states in black phosphorus ribbons with different lattice directions. We design and tune plasmonic polarization converters and electromagnetically induced transparency devices based on the configuration of graphene coupled with 2D black phosphorus. The dependence of devices performance on material parameters, properties of light source, structural parameters and the symmetry breaking is illuminated in detail. Reported results will not only lay a compacted theoretical foundation for ultimate fabrication of plasmonic devices based on graphene coupled with 2D black phosphorus but also offer the useful theoretical guidance for the study on the other new-fashioned 2D materials and the coupling properties of their heterostructures.

迅速兴起的二维层状材料及其异质结为微纳光子学器件研究提供一个崭新的平台。本项目将从理论计算和数值模拟两个方面系统研究石墨烯/二维黑磷间的表面等离激元耦合机理及性能调控机制。比较两种单原子层表面等离激元传播常数的异同点，阐明两者之间有效电磁耦合的临界条件并呈现耦合区域能量再分配特性，实现等离子体波在石墨烯/黑磷间的可控传播和模式转换。分析可耦合条件下引入各向异性黑磷对石墨烯等离激元传播特性与调控维度的影响，研究不同晶格方向黑磷条带间的近场和远场耦合效应，揭示其双连续态与单层石墨烯等离激元近场耦合的法诺线型劈裂与调控机理。设计并调控基于石墨烯/黑磷耦合的等离激元极化转换器和电磁诱导透明器件，阐明器件性能调控与材料参数、光源特性、结构尺寸及对称性破缺的电磁感应关系。研究成果不仅为石墨烯/黑磷耦合的等离激元纳米器件最终设计奠定理论基础，还为研究其它新型二维材料及其异质结耦合特性提供理论参考。

新型的二维层状材料及其异质结为微纳光电子学器件研究提供一个崭新的平台。研究二维材料的极化激元激发及其耦合机制更是器件应用的根本基础。本项目的研究将紧密围绕石墨烯/介质/石墨烯异质结、石墨烯介质/介质/金属异质结、石墨烯/介质/二维黑磷异质结、金属/过渡金属硫化物异质结等结构，从理论分析和数值模拟两个方面深入揭示表面等离激元、声等离激元、激子极化激元等几类二维材料极化激元的形成机制、耦合过程、调控机理。研究内容按照原计划开展，圆满完成了预期目标和预期研究成果。相关成果得到国内外同行的认可，并相继发表在国际高水平期刊 Carbon、Optics Express、Journal of Lightwave Technology、EPL等。基于该项目的支持，协助他人合作培养研究生3名，指导研究生3名，参加本领域国内外会议4次，邀请同行专家指导6人次。.按照原计划，该项目比较了石墨烯和黑磷各自表面等离激元传播常数的异同点，确定了二者可近场耦合的临界条件。研究结果揭示了石墨烯因具有较高的载流子迁移率而支持较强场局域和较低传播损耗的表面等离激元。相比较于黑磷与黑磷的耦合以及石墨烯与黑磷的耦合，石墨烯与石墨烯间的耦合效率和耦合强度相对是最大的。因此该项目以石墨烯/介质/石墨烯异质结为例，重点研究等离激元的远场耦合效应并指出相位调控机制的重要性。.针对研究内容中的“石墨烯/黑磷的等离激元近场耦合”被国内同行以学术论文的形式抢先发表，项目负责人迅速投入到石墨烯/介质/金属异质结的声等离激元、金属/过渡金属硫化物异质结的激子极化激元的近场研究。揭示了近场条件下声化石墨烯等离激元镜像耦合机制，以及源于表面等离激元与半导体激子耦合的激子极化激元形成图像。阐明了调控几类极化激元近场耦合强度的因素。在此基础上设计电磁诱导透明器件、多通道完美光学吸收器，研究了临界耦合机制、法诺共振效应、慢光效应，深化了耦合模理论、传输线理论、米氏散射理论等。该项目的顺利完成为二维材料光电子器件的应用奠定夯实的理论基础。