Polarization-controlled electromagnetically induced transparency analogue based on multipolar resonances

Abstract

An asymmetric metasurface capable of a dynamically controlled electromagnetically induced transparency (EIT) analogue is proposed by changing the polarization direction of the incident light. The metasurface composed of Z-L shape meta-atoms exhibits a narrowband transparency window at 1.858 THz for y-polarization incidence. This EIT window originates from the destructive interference between magnetic dipole (MD), toroidal dipole (TD) and electric quadrupole (EQ) resonances, where the coupling of MD and TD serves as bright mode and EQ acts as dark mode. By varying the polarization angle (φ) of the incident light, the transmission of the dip at 1.856/1.861 THz can be tuned from 0.90/0.95 to 0.08/0.03. Meanwhile, the Q-factor of 640.55 and the group delay of 117.21 ps are achieved at φ = 120°. This work will promote the development of novel multipolar supported EIT metasurfaces.