Characteristic Study Of Surface Plasmon Bragg Filter

Surface plasmon polaritons (SPPs) is an electromagnetic excitation at the interface between metal and dielectric materials. One of the most attractive characteristics of SPPs is the way in which they help us concentrate and channel light in subwavelength structures. As an important branch of surface plasmon waveguides, Metal-Insulator-Metal (MIM) plasmonic waveguide has unique advantages,it has became a research focus in the direction of photonic devices. In this paper, we investigated the transmission characteristics of surface plasmons in metal-insulator-metal waveguide and proposed several plasmonic elements based on metallic waveguide to control the transmission.First, we use the finite-difference time-domain method to investigate the electromagnetic field distribution of TM0 mode in metallic waveguide, this mode can be treated as a quasi-TEM mode,so we presented a general Transfer Matrix Method model for MIM Bragg reflectors and validated our model against FDTD simulations. The result shows that these two kinds of methods agree well. We also discussed the relationship between transmission spectrum and structural parameters of the filter.Then, we investigate the methods to control the transmission spectrum of this metal waveguide filter. By changing slit length, some higher-order spectrum bandgap disappeared. We also designed a wide bandgap Bragg filters by changing the slit width, dielectric material in the waveguide, Bragg wavelength or merger different filters. Finally, we designed a filter which prohibits 1310nm and 1550nm light through.At last, because of the existence of sidelobes in such a kind of filters, the approach that can realize apodization at both the high frequency and low frequency sideband is also explored. We design two kinds of different apodization structure, and discussed their own features using numerical simulation.