Comparative investigations of surface plasmon polaritons on dielectric and metallic gratings

We investigate the properties of Surface Plasmon Polaritons (SPPs) on two kinds of structures: metallic and dielectric gratings loaded on a metallic layer (MM grating and DM grating). The rigorous coupled wave analysis (RCWA) is used for all the simulation in this article. The characteristics of band gap, dispersion relation, reflectivity curves and resonant electric field distributions are comparative simulated and analyzed in MM and DM gratings. Compared with the sticky short-wavelength band edge and complicated surface electric field distributions of MM grating, it is found that the band gap edges of DM grating could be controlled flexibly and the surface fields are more smoothly, which can be used to facilitate the spectral tunability and tailor the optical response of DM structure. This work would provide help for understanding the intrinsic reason of the difference of SPPs in two kinds of structures and basis for choosing suitable structure (MM or DM) of SPPs devices aiming at different functions, especially for designing the dielectric loaded surface plasmon polaritions (DLSPPs) devices.