Impact of arrangement, length and chemical potential on the robustness of graphene induced photonic bandgap in photonic crystals

Abstract

The study of photonic crystals, artificial materials whose dielectric properties can be tailored according to the stacking pattern of their constituents, remains an attractive research area. Very recently, the propagation of light waves in periodic and quasiperiodic graphene embedded dielectric multilayers has also been considered. The presence of graphene between consecutive layers induces the emergence of the so-called graphene induced photonic bandgap. In this article, we employ a transfer-matrix treatment to study the effects of (i) random arrangement of the layers, (ii) length of the multilayer and (iii) chemical potential of graphene on the robustness of the graphene induced photonic bandgap (GIPBG) in one dimensional graphene-embedded photonic crystals. The photonic crystals considered here are composed of two dielectric materials, namely, silicon dioxide (layer A=SiO2) and titanium dioxide (layer B=TiO2). Our numerical results quantitatively show that the random arrangement and length of the multilayers cause minor changes in the bandgap edge of the low frequency GIPBG, i.e., the low frequency GIPBG is robust regarding composition and length of the structures. On the other hand, the chemical potential strongly affects the robustness of the low frequency GIPBG. In fact, the low frequency GIPBG is strongly dependent on the properties of graphene, reinforcing that it is possible to adjust its width and bandgap edge by tuning the chemical potential via a gate voltage.

Keywords

• Photonic crystals
• Graphene
• Random multilayers
• Electromagnetic waves propagation
• Light waves transmission