中国物理B ›› 2021, Vol. 30 ›› Issue (8): 84211-084211.doi: 10.1088/1674-1056/abeee4

所属专题: SPECIAL TOPIC — Optical field manipulation

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Bound states in the continuum on perfect conducting reflection gratings

Jianfeng Huang(黄剑峰), Qianju Song(宋前举), Peng Hu(胡鹏), Hong Xiang(向红), and Dezhuan Han(韩德专)   

  1. College of Physics, Chongqing University, Chongqing 401331, China
  • 收稿日期:2021-02-05 修回日期:2021-03-12 接受日期:2021-03-16 出版日期:2021-07-16 发布日期:2021-08-02
  • 通讯作者: Hong Xiang, Dezhuan Han E-mail:xhong@cqu.edu.cn;dzhan@cqu.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 12074049) and the Fundamental Research Funds for the Central Universities, China (Grant Nos. 2020CDJQY-Z006 and 2019CDXZWL002).

Bound states in the continuum on perfect conducting reflection gratings

Jianfeng Huang(黄剑峰), Qianju Song(宋前举), Peng Hu(胡鹏), Hong Xiang(向红), and Dezhuan Han(韩德专)   

  1. College of Physics, Chongqing University, Chongqing 401331, China
  • Received:2021-02-05 Revised:2021-03-12 Accepted:2021-03-16 Online:2021-07-16 Published:2021-08-02
  • Contact: Hong Xiang, Dezhuan Han E-mail:xhong@cqu.edu.cn;dzhan@cqu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 12074049) and the Fundamental Research Funds for the Central Universities, China (Grant Nos. 2020CDJQY-Z006 and 2019CDXZWL002).

摘要: 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 line. Here we show that bound states in the continuum (BICs) can also be achieved in such systems. Two types of grating structures are proposed to suppress the radiation leakage and hence generate bound states. The first one is a simple grating with broad grooves in which multiple cavity modes are accommodated. Due to the symmetry incompatibility and the destructive interaction mainly from the TM0 and TM1 modes, BICs at the Γ point and at off-Γ points are both realized. The second one is a dimerized grating with two grooves in each unit cell. The destructive interaction between the modes in the two grooves can suppresses the radiation and BICs at the Γ point are observed. The Q factors of the whole bands can be further tuned by the dimerization strength effectively. This 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

Abstract: 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 line. Here we show that bound states in the continuum (BICs) can also be achieved in such systems. Two types of grating structures are proposed to suppress the radiation leakage and hence generate bound states. The first one is a simple grating with broad grooves in which multiple cavity modes are accommodated. Due to the symmetry incompatibility and the destructive interaction mainly from the TM0 and TM1 modes, BICs at the Γ point and at off-Γ points are both realized. The second one is a dimerized grating with two grooves in each unit cell. The destructive interaction between the modes in the two grooves can suppresses the radiation and BICs at the Γ point are observed. The Q factors of the whole bands can be further tuned by the dimerization strength effectively. This work may offer new opportunity for the applications of metallic grating in the low frequency bands.

Key words: bound states in the continuum, perfect conducting grating, mode expansion method, spoof surface plasmon polaritons

中图分类号:  (Diffraction and scattering)

  • 42.25.Fx
42.25.Hz (Interference) 42.79.Dj (Gratings) 73.20.Mf (Collective excitations (including excitons, polarons, plasmons and other charge-density excitations))