Research On The Phenomenon Of SPP’s Enhanced Optical Transmission

Surface plasmon polaritons (SPPs) are the fundamental electromagnetic excitations occurring at the interface between a metal and a dielectric layer, the propagation length of SPPs and the electrical fields excited by surface plasmons around metal structures strongly depend on the shapes and sizes of structures. In recent years, a series of works showed SPP·s novel properties which results from the combine between Surface plasmon polaritons and metal micro-nano structure system. Thus, SPPs is a hot topic of modern physics with wide applications, especially the surface plasmonic photics and the nanophotonics devices based on SPPs have caused extensive concerns of the scientists in the world. SPPs play an important role on nanophotonics. We can also using the property that optical device composed of surface plasmon polaritons can break through the diffraction limit to realize the integration of microelectronics and photons in the same chip. In this paper, the Surface-Plasmon-Enhanced optical transmission in Subwavelength metallic nanohole arrays structure has been focused in this thesis and the main contents are described as follows:(1) The SPP·s fundamental electrical field properties has been studied further. The principle of Surface Plasmon Polaritons excitation has been studied further as well, we also has understand the application field and the Prospect of the Surface Plasmon Polaritons.(2) The transmittance properties of a silver nanowire-helix system has been studied, The transmittance spectrum and steady-state electrical field distribution of the silver nanowire-helix system are investigated in detail using the finite-difference time-domain method. In addition, the effects of the helix structure parameters and the the separation s between the nanowire and helix are also studied, results show that in the nanowire-helix system, surface plasmon polaritons are coupled into the helix or squeezed into the space between the nanowire and helix. The transmittance strongly depends on the topologic shapes of the helix, especially the pitch height. Therefore, the nanowire-helix system provides a new way to detect displacement based on the deformation of the helix in the plasmonic way.(3) In consideration of that the resonant extraordinary optical transmission (EOT) can achieve a narrow transmission, the application of it is restricted, we also studied the nonresonant extraordinary optical transmission (EOT) phenomenon. In this paper, a novel paradigm structure comprising periodic diamond nanohole arrays engraved on a thin gold film is proposed. The transmission properties of the diamond nanohole arrays are calculated using the finite element method. Results show that this paradigm structure facilitates a broadband and enhanced transmission in the infrared region. In addition, the effects of incident polarization and structural parameters on the transmission property are also studied. Then we found The transmission properties of the paradigm structure is strongly depend on the incident polarization and structural parameters, only with the appropriate polarization angle and structural parameters, could the better transmission properties be achieved.(4) In this paper, we proposed a compound structure of the tapered metallic slit embedded with rectangular cavity as well, and its optical properties are investigated by the finite element method. We also compare the optical properties between the tapered metallic slit with rectangular cavity and tapered metallic slit without rectangular cavity. The results show that the compound structure not only can achieve broadband transmission but also leads to a higher transmission than the tapered metallic slit without rectangular cavity. In addition, the effects of the structure parameters and the position of the rectangular cavity on the transmission property are also studied. These results would be helpful for designing metallic slits with high transmission.