The Theoretical Study Of Surface States On The Multilayer Structures

Surface plasmon polaritons (SPPs) is a kind of surface electromagnetic states. The biggest field distribution of SPPs usually is located on the interface between positive-permittivity material and negative-permittivity material. Along the direction perpendicular to the interface, the electromagnetic fields of SPPs are evanscent. SPPs can be excited only for TM polarization and under the light cone. Microstructures based on SPPs can be used to fabricate optical sensors, waveguides, reflectors and anti-reflection devices and so on. In visible and infrared ranges, some noble metals are typical materials with negative permittivity. Microstructures composed of metals and dielectric materials with positive permittivity have small lattice constant which can be far smaller than the wavelength so that the local resonance plays a leading role which excites SPPs to realize the transmission or absorption enhancement. In recent years, researchers pay much attention to the photonic devices and their potential applications based on SPPs and coupling resonances.Graphene is a kind of two-dimensional materials which is composed of one-atom-thick layer of carbon atoms in a honeycomb lattice. Graphenes have many excellent properties, such as structural stability, good electrical conductivity, thermal conductivity and high hardness. Graphene is a potential alternative to silicon for making super tiny transistors and producing future supercomputers and etc. Since graphene has so many special photoelectric properties, many researches have attracted extensive interests.In the second part of the thesis, we theoretically studied transmission properties of the TM polarized electromagnetic waves in the one-dimension metal/dielectric multilayer film structures. The evanescent electromagnetic wave is excited under the total reflection condition using a semi-cylindrical prism. It is found that the wideband perfect transmission can be realized when the metal layer is lossless. Then, we discuss the transmission properties of the microstructure for the real metal with the loss. It is found that there is still enhanced transmission band. Finally, the physical mechanism of the enhanced transmission is investigated according to the electromagnetic field distributions at the special wavelength. Such structure can be used for the preparation of miniature photonic devices.In chapter 3, We have theoretically investigated the electronic resonant tunneling effect in graphene superlattice heterostructures, where a tunable graphene layer is inserted between two different graphene superlattices. It is found that a complete tunneling state appears inside the enlarged wide forbidden gap of the heterostructures by changing the thickness of the inserted graphene layer. In other words, the transmittance of the tunneling mode depends on the thickness of the inserted graphene layer. Moreover, it is found that the frequency of the tunneling mode changes with the variation of the thickness of the inserted graphene but it always located in the overlapped forbidden gap of two graphene superlattices. Therefore, both a perfect transmission peak and a ultra wide forbidden gap with a little overlapped range are realized in such heterostrutures. Furthermore, according to the intensity distributions of the perfect tunneling mode, it is found that the maximum field intensities are localized highly near the interface between the inserted graphene and one graphene superlattice, so the tunneling mode may be as a interface-liked mode. Such structures are significant to fabricate high-Q narrowband electron wave filters.