Research Of Narrow Band Filter Based On Surface Plasmon Polaritons

Recently, the development of microelectronic devices is limited by bandwidth and transmission rate. All-optical integrated optical devices have a mushroom growth, but the devices dimension of the optical devices are micrometer because of diffraction limit. In order to investigate nanometer scale optical devices, the research about nano optics attracts broad attention of researchers in the fields of communications,. information storage, biosensing and so on. One important research field of nano optics is to study the characteristics of different material systems at the nanometer scale. Surface Plasmon Polaritons.(SPP) has become an important branch of nano optics. Surface plasmon polaritons (SPPs) are electromagnetic excitations at the interface of a metal and a dielectric which can propagate along the metal surface with the amplitude decaying into both sides. One of the most attractive aspects is that SPPs can overcome the diffraction limit and can be used to manipulate light at a subwavelength scale. We have a wide use of SPPs in optical storage, potoeching, surface enhancement Raman spectroscopy and so on. One of the base, types of SPP. waveguide is metal-insulator-metal (MIM) structure. In MIM structure, most of the energy is constrained in the intermediate dielectric layer. The width of insulator can reach the subwavelength scale, we can use MM waveguide to localize the light effectively in order to realize potential applications in next generation of integrated photonic devices. In this paper, we did an in-depth study of narrow band filter based on surface plasmon polaritons using finite-different time-domain (FDTD) and defect mode theory. The Specific content of the paper is divided into the following sections:1. Introduced the research background of our paper and the development process of SPPs. Gave a brief description of Drude model. Briefly introduced dispersion relation of SPPs, excitation modes of SPPs and SPPs in multilayer structure. Focused on two basic three-heterostructure, insulator-metal-insulator (IMI) structure and metal-insulator-metal (MIM) structure.2. Gave an introduction of photonic crystal and basic concept of Bragg grating. Discussed the influence of defect mode in photonic crystal and the features of Bragg grating to the performance of waveguide structure.3. A tunable narrow band filter based on a Bragg grating with surface plasmon polaritons is developed and investigated numerically by using the finite-difference time-domain method. By introducing one or more defects to achieve the narrow band filter function. Discussed the structural parameters which can influence the filtering performance, such as the location of the defect, the shape of the defect, the permittivity of. the insulator and so on. We investigated the relationship between resonant wavelengths and the parameters of the structure with defect mode theory and the superposition theory of wave function. The resonant wavelengths in the bandgap are related to the position of defects and the refractive index of the insulator. Our results may provide useful information in the design of tunablenarrow band filters in nano-circuits. Our paper has given a theoreticalbasis to further improve and develop tunable narrow-band filter provides,it also has a certain significance for the simulation and design of opticaldevices based on subwavelength scale.