Numerical Analysis of Multiple Plasmon-Induced Transparency Effects of Side-Coupled Waveguide with Double Loop-Stub

This paper investigates the multiple electromagnetically-induced transparency-like (EIT-like) effects of the ipsilateral, opposite-side, and antisymmetric double loop-stub (LS) resonator side-coupled waveguides. By the finite element method, numerical simulation is conducted on the optical transmission properties of the three waveguides. The results show that the transmission spectrum, magnetic field distribution, and dispersion of the three waveguides strongly depend on structure parameters. Moreover, this paper puts emphasis on the study of the influence of the distance between two adjacent stub resonators or the distance between two horizontal branches of double LS resonators on transmission properties. When the distance decreases, the coupling between two LS resonators gradually increases, and more transmission peaks and dips (i. e. , the stop bands) are observed, which indicates that the multiple EIT-like effects are significantly enhanced. In addition, in the case of the ipsilateral waveguide, when the distance between the two stub resonators is zero, the effects of the vertical branch width, horizontal branch width, and total horizontal branch length on the transmission spectrum are discussed. These side-coupled metal nanowaveguides have potential applications in future integrated optics, such as filters, sensors, and slow light devices.