基于矩形谐振腔MIM波导结构的表面等离子体带阻滤波器

Study of the Surface Plasmon Band-stop Filter Based on the Structure of Rectangular Resonator MIM Waveguide

采用二维时域有限差分法(FDTD)设计并验证了一种新型的基于金属-介质-金属(metal-insulator-metal,MIM)多矩形谐振腔结构的表面等离子体带阻滤波器.该结构由一波导通道和一列平行排列于波导上方的矩形谐振腔组成.当矩形腔的长度对某一波长满足法布里-珀罗(F-P)谐振条件时,该波长的表面等离子体(Surface Plasmon Polaritons,SPPs)将进入腔内并发生耦合共振而被限制在其内,起到滤波的效果.通过调整谐振腔的长度和数量,可以方便地滤掉一个或多个不同波长的光波.与其他结构SPPs滤波器相比,此结构更具有简洁、滤过的波长更窄、更小的能量损耗等优点,该种滤波器可以应用于高集成电路等光学设备.

Abstract. Based on the rectangular resonator metal-insulator-metal （MIM） waveguide structure, we have presented and proven a new type of surface plasmon band-stop filter using the two-dimensional finite- difference time-domain method （2-D FDTD）. This structure consists of a waveguide channel and a column of rectangular cavity resonator,which is parallel to the waveguide. When F-P conditions are met between the length of the rectangular cavity and the wavelength, the surface Plasmon （Surface Plasmon Polaritons, SPPs） of the wavelength will be restricted in the cavity, which results in the filtering effect. By adjusting the length and the number of the resonator, we can easily filter out one or more specific single wavelength. Compared with other structures of SPPs filter, this structure is more concise and can filter narrower wave- lengths with smaller energy loss. It can be applied to optical equipments in high integrated circuit devices.