Topological surface plasmon resonance in deep subwavelength structure

Abstract

We propose a plasmonic topological junction structure that combines topological robustness and subwavelength localization properties. The proposed structure is a junction of two topologically distinguished metal-insulator-metal waveguide gratings. Assuming Au–SiO2–Au waveguide gratings, we theoretically demonstrate a plasmonic Jackiw-Rebbi-state resonance which has substantially small effective mode-field area in the order of 0.1 μm2 at 1560 nm wavelength and requires only 10 periods for fully sustaining the ideal resonance Q-factor of the infinitely large array. Therefore, our proposed approach provides an efficient scheme for creating various plasmonic leaky-mode resonance components that can take advantages of spectral robustness and strong localization properties.