Fig. 1

Schematic illustration of the BIM plasmonic waveguide: a monolayer BDS film is placed at a gap width g away from the silver substrate separated by a dielectric spacer with permittivity ε_r. The TM-polarized plasmonic waveguide mode propagates along the x direction and decays along the y direction. Schematic depiction of the E_x distribution is depicted by the red line