基于双粒子耦合的单层介质柱阵列对电磁波的调控  

Rectifying electromagnetic waves by a single-layer dielectric particle array based on dual-particle coupling

作　　者：郑红霞[1] 周鑫[1] 韩影[1] 俞昕宁 刘士阳[1,2] 

机构地区：[1]浙江师范大学光学研究所,金华321004 [2]复旦大学表面物理国家重点实验室,上海200433

出　　处：《物理学报》2015年第22期124-131,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11274277;11574275);浙江省自然科学基金(批准号:LR16A040001);复旦大学表面物理国家重点实验室开放项目(批准号:KF2013_6);国家级大学生创新创业训练计划(批准号:201410345011)资助的课题~~

摘　　要：基于Mie散射理论和多重散射理论探讨了亚波长介质柱阵列对电磁波的调控.研究结果表明:当在全反射的单层介质柱阵列中引入一个空位缺陷时会产生12%的透射;如果在入射一侧再引入一合适的介质柱时,其透射率可增加至36%,为空位缺陷时的3倍;当在出射一侧对称位置处引入另一完全相同的介质柱时,可以调制透射电磁波的模式,虽然总的透射率没有增加,但向前散射的电磁波能量明显增强.采用这种双粒子耦合体系,在金属柱的表面等离激元共振频率附近也可以实现类似的效果.这些体系结构简单、易于在实验上实现,这对于太赫兹甚至光频段的光子集成线路中的元件设计和光束调控很有意义.Metamaterials, composed of subwavelength building blocks with artificial electric/magnetic response, have attracted the intensive interest due to the unprecedented controllability of electromagnetic （EM） waves and the potential applica- tions. Nonetheless, the resonance of the metallic building block induces a strong loss, severely limiting the performance. Dielectric particle based subwavelength structures provide an alternative choice for the manipulation of EM waves, meanwhile, circumventing the loss problem inevitable for metallic metamaterials, in particular, in optical regime. It is shown that this kind of metamaterial can be used to guide the surface wave with the dielectric particle chain, which is similar to the surface plasmon mediated wave guiding. The structure is also shown to be capable of implementing negative refraction with negligible loss theoretically and experimentally. In addition, the single-layer dielectric rod array can be used to achieve omnidirectional total reflection at subwavelength scale. To further extend the functionality of dielectric based metamaterials and make them more appropriate for integrated optics, a variety of experimentally feasible configurations should be designed. In this work, based on the Mie scattering theory and the multiple scattering theory, we investigate the manipulation of EM waves through a single-layer subwavelength dielectric rod array （SDRA） and particle coupled system. Our results show that by removing the central dielectric rod in the SDRA and at the beam focus, like a vacancy defect, a normal incident transverse electric polarized Gaussian beam is weakly transmitted with an efficiency of less than 12 percent. By further introducing a dielectric rod with optimized parameters on the incident side of the vacancy defect, an enhanced transmitted EM wave with an efficiency of 36 percent is exhibited, nearly triple that with a solely vacancy defect. By adding another identical dielectric rod symmetrically on the outgoing side of the vacancy defect, t

关 键 词：电磁超介质 双粒子耦合 MIE散射理论 多重散射理论 

分 类 号：O441.4[理学—电磁学]