光学变换级联一维光子晶体宽带全向反射镜设计  

Optical Transformed Cascaded One-Dimensional Photonic Crystal Broadband Omnidirectional Reflector

作　　者：梅永[1] 王浩志 王身云[1] Mei Yong;Wang Haozhi;Wang Shenyun(School of Electronics&Information Engineering,Nanjing University of Information Science&Technology,Nanjing 210044,Jiangsu,China)

机构地区：[1]南京信息工程大学电子与信息工程学院,江苏南京210044

出　　处：《光学学报》2025年第1期229-235,共7页Acta Optica Sinica

基　　金：国家自然科学基金(61971231)。

摘　　要：为了实现全向反射镜的小型化,设计一款基于级联结构的一维光子晶体反射镜模型。首先,利用传输矩阵法计算三个单级一维光子晶体结构在横磁波(TM波)照射条件下的全向反射系数,其全向反射带宽分别为433~453 nm、466~488 nm和499~524 nm。然后,将这些单级结构进行级联,计算级联结构的全向反射带宽。计算结果表明:级联结构的全向反射带宽为446~494 nm,宽度为48 nm。最后,采用变换光学原理对级联结构进行压缩变换,实现级联结构的尺寸小型化,并保持全向反射带宽不变。考虑变换介质的可实现性,基于折射率不变性对变换介质进行去磁化变换。所设计的变换介质级联结构光子晶体,不仅有效增加全向反射带宽,也显著减少反射镜的厚度,为全向反射镜的小型化和宽带化提供一种有效方案。Objective One-dimensional photonic crystals(1DPCs) are periodic arrays of dielectric materials that prevent electromagnetic(EM) waves with frequencies within the photonic bandgap(PBG) from propagating.With careful design,certain 1DPCs can exhibit an omnidirectional bandgap that blocks EM waves from all incident angles,for both transverse electric(TE) and transverse magnetic(TM) polarized waves.These types of 1DPCs are known as omnidirectional reflectors(ORs).To increase the bandgap width of OR,a cascaded 1DPC structure can be used.However,such structures become bulky when many 1DPC layers are combined.In this paper,we propose an optical transformed cascaded 1DPC structure that achieves a wide omnidirectional bandgap while minimizing the overall thickness.Methods First,three single-layer ORs based on individual 1DPC structures,illuminated by TM wave,are simulated,and their omnidirectional reflection bands are calculated using the transfer matrix method.The results show reflection bands of 433-453,466-488,and 499-524 nm,respectively.Next,these three 1DPC structures are cascaded to form a wider-band OR.Finally,the thickness of the cascaded structure is reduced using transformation optics principles.The permittivity and permeability of the compressed structure are recalculated,and the magnetic permeability is adjusted to be non-magnetic for ease of fabrication.The omnidirectional reflectance of the transformed cascaded structure is computed using the full-wave simulator HFSS.Results and Discussions The omnidirectional reflection bandwidth of the cascaded 1DPC structure ranges from 446 to 494 nm,with a total bandwidth of 48 nm.The reflection bandwidths at different incident angles for the TM wave are calculated using the transfer matrix method,as shown in Fig.3.The original cascaded 1DPC structure is then compressed to different sizes using transformation coefficients of 0.8,0.5,and 0.1.The dielectric materials required for this transformation are calculated based on the principle of transformation optics.Subsequently

关 键 词：光子晶体 全向反射镜 传输矩阵 变换光学 

分 类 号：TN202[电子电信—物理电子学]