Plasmon-induced multilevel-transparency in two-dimensional hybrid coplanar waveguide

The optical transmission property of a hybrid coplanar waveguide consisting of three quarters of a nanoring (TQNR) and a slot cavity resonator is numerically investigated and theoretically analyzed. In this paper, the apparent multilevel plasmon-induced transparency (PIT) effect can be obtained due to the interaction between the resonance modes of the two elements. Combining the calculated magnetic field distribution with the theoretically fitted parameters, the transparency windows of all resonance modes can be clearly investigated. The results show that the second-order transparency window originates from the destructive interference between the bright and dark mode of the hybrid system, while the first- and third-order transparency windows originate from the suppression effect of the dark mode. As the assessment standard for application, the maximal values of appear at the transmission dips and their highest reaches to near 18. While the reaches to an impressive value 270 at the third-order transparent window, and the sensitivity is as high as 2650 nm RIU−1 at the first-order transparent window. This research provides a guide to the practical applications in the visible and near-infrared light region.