Jiang, Xiao-Qiang; Fan, Wen-Hui; Chen, Xu; Yan, Hui

A simple all-dielectric metasurface with symmetric structure, exhibiting strong toroidal dipole (TD) resonance and ultrahigh quality factor (Q-factor), is proposed. The physical mechanisms of the TD resonance are investigated by calculating the electromagnetic field and the scattering power of multipoles. Simulated results demonstrate that the Q-factor is up to 3.71 x 10(4) and the corresponding figure of merit is 636.7. Moreover, the TD resonance can be excited under both x- and y-polarized incident terahertz waves due to the symmetric structure. The remarkable performances make the proposed metasurface has feasible capability for biological and chemical sensing in terahertz range.

The result was published on APPLIED PHYSICS EXPRESS. DOI: 10.35848/1882-0786/ac27b7