Low-voltage controlling high order plasmonic modes based on graphene/metal electrodes

Abstract

To improve the compatibility of the nanophotonic device with the electronic device, a kind of hybrid system based on graphene/metal electrode is demonstrated and characterized by both coupled mode theory and numerical simulation. Our results show that, assisted by metallic slits, multiple high order plasmonic resonant modes, including even and odd ones, are efficiently excited in graphene ribbons. The slits perforated in a metal electrode act as magnetic dipole sources and break the structural symmetry in individual graphene ribbons. Due to nano-sized space between graphene and metal gate electrodes, low voltages are required to dynamically control plasmonic modes of such hybrid system. At last, based on Salisbury effect, a low-voltage controlling multi-band absorber are successfully designed. The proposed structure would find potential applications in the field of integrated photonics which are compatible with electronic technology, specifically in low-voltage controlled plasmonic devices such as tunable multiband mid-infrared absorbers, modulators, biosensors, photonic memory cells etc.