Ultrawideband air-core plasmonic slow-light waveguide with ultralow high-order dispersion

We propose a surface plasmonic waveguide that consists of a metal–dielectric–metal structure and an air-core which are sandwiched in both metals and dielectric material. Numerical results show that the waveguide is able to confine the surface plasmonic modes in a very small air area and achieve slow light with a group velocity of 0.0086 c and cancelled even-orders dispersion over the ultrawideband of 21 THz.