Plasmon Polaritons In Multilayered Structures

Surface plasmon polaritons(SPPs) find important applications in the development of the integrated optics owing to their outstanding features, such as breaking through the diffraction limit, and confining the electromagnetic energy at subwavelength scale. Surface plasmon waveguide, which has received a lot of attention, is one of the important applications of the SPPs.Based on the basic electromagnetic field theory and the hydrodynamic model, the impact of nonlocal response on the SPPs in an asymmetrical structure is studied. Taking the nonlocal response into consideration, we discuss the dispersion relation and the propagation properties of the SPPs. We find that in the nonlocal case, the SPPs possess almost the same behaviors as in the local one; only for the larger wave number, the higher frequency or the thicker polymer film, does the nonlocal response affect markedly the dispersion and the propagation properties of the SPPs.Graphene is a novel plasmonic material that can find its potential applications in the range from terahertz to mid-infrared frequencies. Therefore, using Maxwell’s equations, we discuss the SPPs in several graphene-based structures. It is found that the SPPs in these structures are of the almost similar propagation properties. Comparatively, the symmetric structure is more conducive to the propagation of the SPPs, and the propagation length of the SPPs can be efficiently improved by decreasing the frequency of the incident light or by increasing graphene’s Femi level. Adjusting graphene’s Femi level is an efficient way to control the dispersion and propagation properties of the SPPs.The above findings might be helpful to the design of plasmonic devices working at nanometer or subnanometer scale.