Graphene based photonic crystals including anisotropic defect layers with highly tunable optical responses in infrared frequency range

Optical features of three one dimensional photonic crystals are studied theoretically. First structure which consists of SiO2 slabs separated by graphene sheets is considered as an ideal crystal with tunable response. Adding anisotropic liquid crystal (LC) layers inside the ideal structure, two defective crystals are also proposed to assess their potential of being used in photonics. Dependence of the crystals transmittance to periods of the layers as well as size of the SiO2 and LC slabs are studied at first. Extracting the optimum values for these structural parameters, tunability of the optical response of the proposed crystals by using externally controllable parameters such as: optical axis of the anisotropic layer, light incident angle, crystal temperature and graphene layer chemical potential are evaluated systematically. Results clearly reflect that all suggested crystals might be useful to support the increasing demands of optical integrated circuit technology for adjustable photonic elements.