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Bound states in the continuum in metal-dielectric photonic crystal with a birefringent defect

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Chinese Physics B 2022年第10期31卷 177-181页

作者： Hongzhen Tang Peng Hu Da-Jian Cu Hong Xiang dezhuan han Department of Physics and Chongqing Key Laboratory for Strongly Coupled Physics Chongqing UniversityChongqing 401331China Chongqing Key Laboratory of Core Optoelectronic Devices for Quantum Communication Chongqing Optoelectronics Research InstituteChongqing 400060China

By using the difference of the band structure for the TE and TM waves in the metal-dielectric photonic crystals beyond the light cone and the birefringence of the anisotropic crystal,a one-dimensional photonic system is constructed to realize the bound states in the continuum(BICs).In addition to the BICs arising from the polarization incompatibility,the Friedrich-Wintgen BICs are also achieved when the leaking TM wave is eliminated due to the destructive interference of its ordinary and extraordinary wave components in the anisotropic crystal.A modified scheme favorable for practical application is also *** scheme for BICs may help to suppress the radiation loss in the metal-dielectric photonic crystal systems.

关键词： bound state in the continuum birefringence metal-dielectric photonic crystal interference

Bound states in the continuum on perfect conducting reflection gratings

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Chinese Physics B 2021年第8期30卷 25-30页

作者： Jianfeng Huang Qianju Song Peng Hu Hong Xiang dezhuan han College of Physics Chongqing UniversityChongqing 401331China

Bound states can be supported on the surface of a periodically corrugated perfect conductor known as spoof surface plasmon polaritons with their dispersion curves reside below the light *** we show that bound states in the continuum(BICs)can also be achieved in such *** types of grating structures are proposed to suppress the radiation leakage and hence generate bound *** first one is a simple grating with broad grooves in which multiple cavity modes are *** to the symmetry incompatibility and the destructive interaction mainly from the TM_(0)and TM_(1)modes,BICs at theΓpoint and at off-Γpoints are both *** second one is a dimerized grating with two grooves in each unit *** destructive interaction between the modes in the two grooves can suppresses the radiation and BICs at theΓpoint are *** Q factors of the whole bands can be further tuned by the dimerization strength *** work may offer new opportunity for the applications of metallic grating in the low frequency bands.

关键词： bound states in the continuum perfect conducting grating mode expansion method spoof surface plasmon polaritons

Bound States in the Continuum in One-Dimensional Dimerized Plasmonic Gratings

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Chinese Physics Letters 2020年第6期37卷 98-102页

作者： Chen Huang Qian-Ju Song Peng Hu Shi-Wei Dai Hong Xiang dezhuan han College of Physics Chongqing UniversityChongqing 401331China

A simple one-dimensional subwavelength plasmonic grating can support symmetry protected bound states in the continuum(BICs),but not necessarily for the non-symmetry protected *** dimerizing the lattice,nonsymmetry protected BIC can be supported on the dimerized grating and can be tuned *** mechanism for the BICs in the dimerized grating is interpreted in the viewpoint of interference between the electromagnetic multipoles.

关键词： symmetry protected dimer

PT Symmetry Induced Rings of Lasing Threshold Modes Embedded with Discrete Bound States in the Continuum

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Chinese Physics Letters 2021年第8期38卷 50-56页

作者： Qianju Song Shiwei Dai dezhuan han Z.Q.Zhang C.T.Chan Jian Zi College of Physics Chongqing UniversityChongqing 401331China Department of Physics Hong Kong University of Science and TechnologyClear Water BayHong KongChina Department of Physics Key Laboratory of Micro-and Nano-Photonic Structures(MOE)and State Key Laboratory of Surface PhysicsFudan UniversityShanghai 200433China

It is well known that spatial symmetry in a photonic crystal(PhC)slab is capable of creating bound states in the continuum(BICs),which can be characterized by topological charges of polarization ***,we show that when a PT-symmetric perturbation is introduced into the PhC slab,a new type of BICs(pt-BICs)will arise from each ordinary BIC together with the creation of rings of lasing threshold modes with pt-BICs embedded in these *** from ordinary BICs,the Q-factor divergence rate of a pt-BIC is reduced and anisotropic in momentum ***,pt-BICs can even appear at off-high symmetry lines of the Brillouin *** pt-BICs also carry topological charges and can be created or annihilated with the total charge conserved.A unified picture on pt-BICs and the associated lasing threshold modes is given based on the temporal coupled mode *** findings reveal the new physics arising from the interplay between PT symmetry and BIC in PhC slabs.

关键词： polarization symmetry lasing

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高功率波段基于零折射率材料的波前相位改善

太赫兹科学与电子信息学报 2018年第5期16卷 835-839页

作者：张莉廖勇向红韩德专山西大同大学物理与电子科学学院山西大同037009 中国工程物理研究院应用电子研究所四川绵阳621999 重庆大学物理学院重庆400044

零折射率材料作为超材料的一种在微波辐射中有广泛应用。为实现高性能的小型化天线,分析了零折射率材料的产生机理,设计了一种高功率金属网格材料天线透镜。数值模拟表明,零折射率材料透镜覆盖于一Ku波段喇叭天线口面时,可以改善喇叭天... 详细信息

零折射率材料作为超材料的一种在微波辐射中有广泛应用。为实现高性能的小型化天线,分析了零折射率材料的产生机理,设计了一种高功率金属网格材料天线透镜。数值模拟表明,零折射率材料透镜覆盖于一Ku波段喇叭天线口面时,可以改善喇叭天线波前相位,将喇叭天线的球面波前相位调制为较均匀的平面波,增益可提高2.27dB,喇叭天线的功率容量可达到610MW。研究了材料的层数n、层距h、周期a以及金属线半径r对S参数的影响,得到了所要求频率的最优材料结构。

关键词：超材料高功率波段零折射率材料喇叭天线

神秘而美丽的光影世界——中国科学院院士、南京大学教授祝世宁报告会

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大学科普 2019年第3期13卷 9-13页

作者：王俊韩德专重庆大学物理学院中国重庆

在重庆大学90华诞即将来临之际,中国科学院院士、南京大学教授祝世宁老师在2019年7月1日党的生日这一天来到重庆大学虎溪校区,为重大学子开展了一场题为“Ignite Your Ideas-变革中的成像新技术”的宏观学术交流即高端科普报告。祝院士... 详细信息

在重庆大学90华诞即将来临之际,中国科学院院士、南京大学教授祝世宁老师在2019年7月1日党的生日这一天来到重庆大学虎溪校区,为重大学子开展了一场题为“Ignite Your Ideas-变革中的成像新技术”的宏观学术交流即高端科普报告。祝院士细致严谨的报告内容与幽默风趣的表达方式深深地吸引了在场的每一位师生,会场内时不时地传出听众们的笑声,大家津津有味地跟随着祝院士一起走进了一个神秘而美丽的光影世界。

关键词：中国科学院院士南京大学教授世宁幽默风趣学术交流重庆大学光影

Optical bound states in the continuum in periodic structures:mechanisms,effects,and applications

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Photonics Insights 2024年第1期3卷 1-26页

作者： Jiajun Wang Peishen Li Xingqi Zhao Zhiyuan Qian Xinhao Wang Feifan Wang Xinyi Zhou dezhuan han Chao Peng Lei Shi Jian Zi State Key Laboratory of Surface Physics Key Laboratory of Micro-and Nano-Photonic Structures(Ministry of Education)and Department of PhysicsFudan UniversityShanghaiChina State Key Laboratory of Advanced Optical Communication Systems and Networks School of ElectronicsPeking UniversityBeijingChina College of Physics Chongqing UniversityChongqingChina Institute for Nanoelectronic devices and Quantum computing Fudan UniversityShanghaiChina Collaborative Innovation Center of Advanced Microstructures Nanjing UniversityNanjingChina Shanghai Research Center for Quantum Sciences ShanghaiChina

Optical bound states in the continuum(BICs)have recently stimulated a research boom,accompanied by demonstrations of abundant exotic phenomena and *** ultrahigh quality(Q)factors,optical BICs have powerful abilities to trap light in optical structures from the continuum of propagation waves in free *** the high Q factors enabled by the confined properties,many hidden topological characteristics were discovered in optical *** in periodic structures with well-defined wave vectors,optical BICs were discovered to carry topological charges in momentum space,underlying many unique physical *** high Q factors and topological vortex configurations in momentum space enabled by BICs bring new degrees of freedom to modulate *** have enabled many novel discoveries in light-matter interactions and spin-orbit interactions of light,and BIC applications in lasing and sensing have also been well explored with many *** this paper,we review recent developments of optical BICs in periodic structures,including the physical mechanisms of BICs,explored effects enabled by BICs,and applications of *** the outlook part,we provide a perspective on future developments for BICs.

关键词： bound state in the continuum light trapping topological charge polarization vortex momentum space light field manipulation photonic crystal slab nanophotonics

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近场的分类及其与静态场的关系

物理与工程 2024年第2期34卷 153-160页

作者：许书侨詹影唐誉婷韩德专重庆大学物理学院重庆401331 南京大学物理学院江苏南京210093

在局域源所产生的电磁场中,以波长为特征长度可以引入两个重要概念:近场和远场。准静态场是另一重要概念。回溯人类对电磁场的认识过程,从一开始分立的静态电/磁场,到麦克斯韦方程组所描述的完整的运动电磁场,经历了认识的飞跃。有限的... 详细信息

在局域源所产生的电磁场中,以波长为特征长度可以引入两个重要概念:近场和远场。准静态场是另一重要概念。回溯人类对电磁场的认识过程,从一开始分立的静态电/磁场,到麦克斯韦方程组所描述的完整的运动电磁场,经历了认识的飞跃。有限的时间频率是运动电磁场的重要特征量。本文以不同维度的辐射源为例,分析了其产生的近场和远场,区分了两种产生近场的机制,并阐述了近场和静态场的关系。最后,本文以介质平板中的法布里-珀罗共振和金属颗粒的表面等离激元共振为例,揭示了不同维度下近场对能量储存的贡献及其与不同维度微腔的品质因子巨大差异的直接关系。

关键词：近场静态场品质因子维度性格林函数

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复虹现象的实验研究

物理与工程 2023年第1期33卷 101-106页

作者：彭子云漆元臻李泽宇梁颖向红韩德专重庆大学大学物理实验教学中心重庆401331

彩虹是一种常见的大气光学现象,在一定天气条件下,在彩虹的附近还会出现附加的弧形彩色条纹,这就是复虹。目前关于复虹的实验研究还十分有限。本文从集体散射与单体散射两方面对复虹现象进行了实验研究。通过水雾光散射再现了复虹现象,... 详细信息

彩虹是一种常见的大气光学现象,在一定天气条件下,在彩虹的附近还会出现附加的弧形彩色条纹,这就是复虹。目前关于复虹的实验研究还十分有限。本文从集体散射与单体散射两方面对复虹现象进行了实验研究。通过水雾光散射再现了复虹现象,并测量统计了水滴尺寸及其分布对复虹的影响。然后通过单水滴光散射实验,研究了不同照明波长、不同水滴尺寸下的复虹现象,从微观上解释了复虹的形成机理。我们还利用散射理论计算研究了水滴尺寸及其统计分布对复虹效果的影响,计算结果进一步证实了实验结论的正确性。

关键词：复虹水滴尺寸分布色散米氏散射