探究四聚体超表面中多极准连续域束缚态的调控机制  

Exploring the tuning mechanism of multipolar quasicontinuous domain bound states in tetramer metasurface

作　　者：孟祥裕 李涛 余彬彬 邰永航[1] Meng Xiang-Yu;Li Tao;Yu Bin-Bin;Tai Yong-Hang(Yunnan Key Laboratory of Optoelectronic Information Technology,Yunnan Normal University,Kunming 650500,China;Wenzhou Key Laboratory of Biophysics,Wenzhou Institute,University of Chinese Academy of Sciences,Wenzhou 325000,China;Oujiang Laboratory(Zhejiang Lab for Regenerative Medicine,Vision and Brain Health),Wenzhou 325000,China)

机构地区：[1]云南师范大学,云南省光电信息技术重点实验室,昆明650500 [2]国科温州研究院(温州生物材料与工程研究所),温州市生物物理重点实验室,温州325000 [3]瓯江实验室(再生调控与眼脑健康浙江省实验室),温州325000

出　　处：《物理学报》2024年第10期321-336,共16页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:62365017);浙江省自然科学基金(批准号:LZ23A040004);云南省优秀青年基金(批准号:202301AW070001)资助的课题。

摘　　要：本文设计了由四聚长方体组成的全介质超表面,其中每个长方体刻蚀两个椭圆柱并填装空气.当分别为超表面单独引入面内对称破缺、位移扰动和周期扰动时,可在近红外波段产生稳健的准连续域束缚态模式(quasi-bound states in the continuum).通过测量准BIC (quasi-BIC)模式的谐振波长,计算准BIC模式的Q因子(quality fector)与不对称参数的关系,可进一步证实不对称参数对准BIC共振频率和Q因子的可调谐性.在此基础上,当同时引入面内对称破缺、位移扰动和周期扰动时,可获得5个高Q因子的准BIC模式.共振峰的数量、位置以及Q因子都可通过调整面内破缺、位移扰动和周期扰动的程度进行调控.该超表面的设计可为传感器的多参数传感以及灵敏度等性能的提升提供一种全新思路.High-quality factor(high-Q)resonance has broad prospects in applications such as in narrow-band filtering,slow-light devices,and nonlinear optics interaction enhanced to highly sensitive sensing.Previous methods of designing high-Q resonance suffered intrinsic drawbacks such as high-volume cavities or large-scale bending radii.However,recently,a new approach to designing high-Q resonances has begun to attract public attention on the basis of asymmetric metasurfaces that are related to the bound states in the continuum(BIC)phenomenon.Constructing BIC resonance in electromagnetic metasurface can generate sharp resonant transmission peak.Therefore,there is growing interest in utilizing BIC to achieve metasurface with high-Q.However,most of existing studies are based on single BIC,and few studies focusing on multiband BICs and multiple forms of symmetry breaking.In this work,we propose an all-dielectric metasurface composed of tetrameric cuboids.By etching two elliptical cylinders in each cuboid,the metasurface can simultaneously support in-plane symmetry breaking,displacement perturbations and periodic perturbations.We first use multipole calculations to analyze the physical mechanism by which the metasurface generates quasi-BIC under these three conditions.It is confirmed that the Q factor and resonant peak position of quasi-BIC can be controlled by adjusting the asymmetry parameters.Subsequently,we introduce the in-plane symmetry breaking,displacement perturbations and periodic perturbations into the metasurface simultaneously and generate five quasi-BIC modes,whose numbers and positions can be flexibly adjusted,and the largest Q factor is 58039.In summary,this work provides a new practical design concept for realizing high-Q all-dielectric metasurfaces,which can be used to improve the sensitivity of multi-parameter sensors.

关 键 词：超表面 准连续域束缚态 对称破缺 

分 类 号：O441.4[理学—电磁学]