Propagation Properties Of Surface Plasmonic Filter With Slot Depth Modulated By A Sine Function

With the rapid development of the science and technology, human beings have entered into the information era. The speed of information transmission, the speed of information processing and the extent of information application, are geometrically growing, then how to faster processing of these information is critical.Although the traditional electronic circuits based on metal interconnect technology can achieve a high degree of integration, but due to the time delay phenomenon and the heating problem in the RC oscillation circuit, signal transfer rate and processing speed in the electronic circuits is difficult to meet the requirements of ultra large capacity and ultra high-speed.Currently, the mainstream view believe that, with the photon as information carrier, optical circuits can effectively solve the problem of ultra large capacity and ultra high-speed. Unfortunately, at present, due to the optical waveguide devices in the optical circuit is limited by the diffraction limit and the lateral scales is limited to the order of the wavelength of light, the degree of the integration of the optical circuits is not able to reach as high as electronic circuit.In recent years, people found that, by the means of surface plasmon nanophotonics, many novel surface plasmonic components can be made. These components can be used to overcome the diffraction limit and control the transmission behavior of the photon. Using these components, not only can achieve ultra large capacity and ultra high speed optical signal transmission, but also can achieve ultra high density integration. It is an effective way to achieve all-optical chip.In this dissertation, surface plasmon nanophotonics, surface plasmon nanophotonic components and MIM surface plasmonic waveguides were reviewed firstly, and then an overview of the research status of the surface plasmonic filters based the MIM surface plasmonic waveguides were focused on, the structural model of MIM surface plasmonic filter with slot depth modulated by a Sinc function were introduced, a simple introduction of the two-dimensional finite difference time domain method (2D-FDTD) which includes the dispersion medium were made. Finaly, the propagation properties of this surface plasmonic filter were analyzed in detail in the1.55μm wave band and the0.55μm wave band by using the2D-FDTD method.The primary coverage of this dissertation are:(1) The dependence of transmission characteristics on the geometrical parameters of surface plasmonic filter with solt depth modulated by a Sinc function in the1.55μm wave band. The results show that, in thel.55μm wave band, compared with the filter without the Sinc function modulation, the right side of the forbidden band edge of the transmission spectrum of the filter with solt depth modulated by the Sinc function is steeper and filter performance is better. The transmission characteristics were affected obviously by the maximum depth, the width, the number of periods of the slots, the width of the horizontal channel and the height of the Sinc function, and indistinctively by the half-wide of the major petals of the Sinc function.(2) The dependence of transmission characteristics on the geometrical parameters of surface plasmonic filter with solt depth modulated by a Sinc function in the0.55μm wave band. The results show that, in the0.55μm wave band, compared with the filter without the Sinc function modulation, the transmittance of the forbidden band is close to0, the transmittance of the pass band at the right of the forbidden band is improved, it’s filtering performance is better. The transmission characteristics were affected obviously by the maximum depth, the width, the number of periods of the slots, the width of the horizontal channel and the height of the Sinc function, and indistinctively by the half-wide of the major petals of the Sinc function.(3) The transmission characteristics of the surface plasmonic filter with solt depth modulated by a Sinc function are compared in the1.55μm wave band and in the0.55μm wave band. The results show that, for the optimized surface plasmonic filter with solt depth modulated by a Sinc function in the1.55μm wave band, the forbidden bandwidth is narrower and the transmittance of the band pass is lower in the0.55μm wave band. Generally speaking, the filtering effect of this filter in the0.55μm wave band is poor.These studies will provide some theoretical basis for the design, fabrication and application of the filters based on MIM surface plasmonic waveguides.