Open AccessEfficient magnetic-coupling excitation of LSSPs on high-Q multilayer planar-circular-grating resonators
Author(s) -
Siqi Li,
Cheng Du,
FengYuan Han,
FanHong Li,
ZiWen Zhang,
ZiChao Gao,
PuKun Liu
Publication year - 2021
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.432721
Subject(s) - resonator , planar , excitation , coupling (piping) , optics , grating , materials science , dissipation , inductive coupling , q factor , magnetic field , surface plasmon , electromagnetic field , plasmon , optoelectronics , physics , computer science , computer graphics (images) , quantum mechanics , metallurgy , thermodynamics
Recently, ultrathin localized spoof surface plasmon (LSSP) resonators are found to have intrinsic defects of relatively low quality factors (Q-factors) because of unavoidable material and radiation losses. In this paper, multilayer structures of planar-circular-grating resonators and their magnetic-coupling schemes are proposed to achieve effective excitation of high-Q LSSPs modes. By adopting the multilayer structures with air between the layers, the power dissipation effected by both material and radiation losses is significantly suppressed. Experimental results show that the Q-factors could reach more than 200 and the excitation efficiencies could reach more than 90%. Numerical simulations show the distribution of the electromagnetic field and illustrate the principle of magnetic coupling. Besides, the Q-factors of resonators with different structural parameters were measured and analyzed. This study aims to provide some inspirations on planar gyro-devices and to improve the performance of existing applications, such as sensors and filters.