Transformation of twin-peak electromagnetically induced transparency to twin-peak electromagnetically induced absorption based on magnetic dipole and dielectric resonator

Abstract

This paper puts forward the transmission from twin-peak electromagnetically induced transparency (EIT) to twin-peak electromagnetically induced absorption (EIA), while it is rare to see the transformation between EIT and EIA in metastructure (MS) in one device in previous articles. With the incidence of TE waves, two transparent windows are generated, ranging from 0.382 THz to 0.986 THz which are separated by 0.604 THz, when the conductivity of vanadium dioxide (VO2) is set to 10 S/m. Two peaks reach 0.864 and 0.934, respectively, accompanied by the largest group delays of the two peaks being 7.55 and 4.54 ps. In addition, VO2 blocks in the metallic state will affect interference paths between energy levels, contributing to the formation of EIA, then maintaining a common absorption of 0.607 at 0.429 THz and 0.904 at 0.678 THz. Under the combined action of the dielectric resonator and metal resonator, the conversion from bimodal EIT to bimodal EIA is hardly been researched, at the same time, the adoption of the circuit model and the four-level theory proves the rationality of the model. The transformation from EIT to EIA is aroused by changing the state of VO2, promising broad prospects in multifunctional devices.