Tunable wave localization for Tamm modes in graphene-based photonic crystals

In this work, we demonstrate the existence of TE polarized surface Bloch modes localized at the boundary of semi-infinite graphene-based photonic crystal and homogeneous dielectric. Imposing an alternate low-high doping level on graphene layers along the multilayer, it is possible to open bandgaps where mode localization can be achieved for TE polarization. The surface modes reported here exist in the low terahertz regime with a corresponding long decaying length and close to allowed band. Due to the tunable gap characteristics of the periodic structure proposed, an on-off switch for TE polarized surface Bloch modes can be achieved. We proved that TE polarized surface mode excitation can be achieved by attenuated total reflection technique in the Otto configuration, making them suitable for experimental probing. Fermi levels considered in this work lie in the range 0.2 eV < μ < 0.8 eV, which is experimentally achievable in electrical gated configurations.