石墨烯等离激元的激发、低损耗传输与外磁场调控研究

Graphene plasmon has important prospect of applications in the terahertz to mid-infrared spectrum. The method of exciting graphene plasmon, transmission with low loss and its manipulation play a crucial role in determining whether it could be applied widely in the field of nano-phoelectronics. Based on the theory methods such as finite element method and experimental fabrication as well as measurement, this proposed project aims to study the mechanisms of excitation of surface plasmon polaritons (SPPs) and volume plasmon polaritons (VPPs), transmission with low loss and its manipulation with external magnetic field. The main contents are the followings: (1)To investigate the mechanism of excitation and transmission with low loss for SPPs based on the coupling between graphene SPPs and surface phonons polariton of polar substrate. (2) To study how excite and travel with low loss for VPPs by combining the interaction between phonon of substrate and surface plasmon, the edge mode and edge magnetoplasmons resonance in graphene-dielectric multilayer structures. (3) To attain an effective method for manipulation of the polarization of incidence wave by introducing external magnetic filed into the coupled system between graphene surface plasmon and phonon of substrate. The planned investigations will provide new knowledge on the interaction mechanism between electromagnetic wave and graphene at deep subwavelength dimension. The possible results are important and helpful to move forward the development of nanophotonic devices such as optoelectronic modulator, magneto-optical devices, etc.

石墨烯等离激元在中红外至太赫兹波段具有重要的应用前景，如何有效地激发石墨烯等离激元，实现低损耗传输及调控是它在未来纳米光电子领域能否获得广泛应用的关键。本申请项目以有限元方法等理论计算为基础，结合实验加工和测量，研究石墨烯表面等离激元和体等离激元的激发、低损耗传输，以及外磁场作用下的调控机理。主要包括：(1）探索基于表面声子激元共振的石墨烯表面等离激元激发和低损耗机制；（2）通过表面等离激元与极化介质声子相互作用及边模式、边磁等离激元耦合的途径，实现石墨烯-介质多层结构中体等离激元的激发和低损耗传输；（3）引入外磁场作用于衬底声子与石墨烯表面等离激元耦合体系，通过延长载流子衰减寿命获得大角度的偏振调控效应。项目拟开展的工作，对于理解深亚波长尺度下电磁波与石墨烯的相互作用机制将提供新的知识。研究结果对于推动基于石墨烯的光调制器、磁光器件等纳米光子器件的研发，具有重要指导意义和价值。

石墨烯等离激元在中红外至太赫兹波段具有重要的应用前景，如何有效地激发石墨烯等离激元，实现低损耗传输及外场调控对于它在未来纳米光电子领域的应用具有重要意义。基于有限元数值模拟，我们就上述问题做了比较系统的研究，获得了一些有意义的结果。课题组与阜阳师范大学合作者共同设计了一类由石墨烯条带组成的有限周期结构，通过邻近石墨烯条带的耦合，一种类声子激元色散的表面等离激元被激发，并在理论上演示了基于外加电压控制的石墨烯表面等离激元开关。我们与合作者研究了在介质光栅覆盖石墨烯片层，在光栅的导模共振下激发形成表面等离激元驻波，获得多个吸收共振的电磁共振模式；课题组设计了石墨烯圆盘-二氧化硅多层结构，通过非线性光学作用激发了三倍频的非线性表面等离激元模式。在石墨烯表面等离激元的低损耗传输方面，我们研究了石墨烯覆盖于介质微腔阵列结构，发现导模激发的高阶共振模式具有超高的品质因子和优异的传感性能。另外我们也考虑了石墨烯与低损耗的介质超表面toroidal共振模式的耦合，实现了外加电压对结构透射谱的动态调控。在外磁场的调控方面，我们设计了石墨烯圆盘的多层结构和平面六聚体结构，利用同相共振的亮模式增强表面等离激元偶极子共振强度，我们理论演示了外磁场作用下显著增强的法拉第效应；利用暗模式的反向共振增强光与石墨烯超表面的相互作用，我们发现了增强的磁圆二色性。. 课题组共发表SCI收录论文8篇，其中Advanced Optical Materials 1篇， Optics Letters 1篇、Optics Express 1篇、Journal of Lightwave Technology 2篇，Optics Materials Express，Journal of Physics D:Applied Physics, Nanomaterials各1篇。所发论文已得到国内外同行的多次正面引用，发表于Optics Letters关于石墨烯表面等离激元驻波激发与共振吸收的论文他引已达110余次，课题组所发表论文总他引140余次。项目取得的研究结果，对于理解深亚波长尺度下电磁波与石墨烯的相互作用机制将提了供新的认识。研究结果对于推动基于石墨烯的光调制器、磁光器件等纳米光子器件的研发，具有参考意义。