Electromagnetic Wave Propagation Properties In The Complex Structure Based On Graphene

Surface Plasmon-Polarition (SPP) is an efficient way to break through the diffraction limit of traditional optical systems. It becomes more and more important in the development of the integrated optics. SPPs propagating along the noble metal have many disadvantage factors which limit the development of SPPs. Graphene as a kind of novel plasmonic materials have more tunable parameters, the lower loss and the better field local features as compared with the noble metal. Therefore, the research on the characteristics of graphene-based SPPs will provide theoretical support for the development and applications of new SPPs device.We study properties of SPPs in the graphene sheet sandwiched between an anisotropic Kerr-type nonlinear medium and a linear isotropic medium and in a gyroelectric slab sandwiched between two graphene layers, where the external static magnetic field is applied in the Voigt geometry. Following Maxwell's equations and the boundary conditions and modeling graphene as an infinitesimally thin surface conductivity, we derive the dispersion relation of SPPs. The numerical results indicate that in the nonlinear case, the dispersion relations of the SPPs exhibit "bistability" behavior when the propagation constants are smaller than their critical values. The dispersion and propagation properties of the can be efficiently controlled by changing graphene's chemical potential, the optical intensity or the nonlinearity coefficient. In the case of gyroelectric slab, it is shown that the dispersion characteristics and propagation lengths of the SPPs for both the optical and the acoustic branches can be tuned flexibly by the external magnetic field and graphene's chemical potential, and that the nonreciprocal properties of the SPPs caused by the external magnetic field are rather obvious. The results provide a method for adjusting and improving the dispersion and propagation properties of the SPPs, which might be helpful for the design of the related plasmonic devices.