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 st...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 TM_(0)and TM_(1)modes,BICs at theΓpoint and at off-Γpoints 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 theΓpoint 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.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.12074049)the Fundamental Research Funds for the Central Universities,China(Grant Nos.2020CDJQY-Z006 and 2019CDXZWL002).
文摘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 TM_(0)and TM_(1)modes,BICs at theΓpoint and at off-Γpoints 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 theΓpoint 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.
