新型表面等离子激元波导滤波器特性研究

发布时间：2018-01-19 15:09

本文关键词： 表面等离子体有限单元法传输特性金属-介质-金属波导结构等离子体滤波器　出处：《南京邮电大学》2015年硕士论文　论文类型：学位论文

【摘要】：表面等离子体(surface plasmons,SP)是一种在金属表面存在的自由振动的电子与光子互相作用产生的沿着金属表面传播的电子疏密波。由于具有近场局域增强,突破衍射极限等特性,其成为近年来的一个研究热点。各种SPP波导相继被报道,从结构上大致分为金属-介质-金属(MIM)型波导与介质-金属-介质(IMI)型波导两种类型,其中MIM型波导结构与IMI型结构相比,可以实现亚波长传输,缩短波导间距及制作简单等特点,有利于实现微纳光子集成。本文在400 nm至2000 nm的波长范围内,研究了波导几何尺寸对于MIM型表面等离子体波导滤波器工作特性的影响,并提出了一种基于MIM型表面等离子体波导结构的窄带滤波器的设计方案。首先利用有限单元法分析了基于MIM型表面等离子激元波导的传输特性,得到了模式有效折射率及传输长度随夹层宽度及激励波长的变化关系曲线。对基于MIM结构的含支节表面等离子激元波导滤波器的透射特性进行仿真,分析结果表明:双侧支节波导结构透射率曲线比单侧支节具有更宽的阻带,此外当双侧支节位置发生偏移时透射率曲线的通带与阻带的边沿将更加陡峭,适合于带阻型滤波器的设计。在此基础上,通过引入两种交错型支节来实现基于MIM波导的表面等离子激元窄带滤波器,并对其透射率曲线进行数值计算,结果显示,支节长度可以影响阻带和通带的中心波长,支节长度差可以钳制透射峰的宽度。这一结论为光子集成回路中窄带滤波器的设计提供了有价值的参考。
[Abstract]:Surface plasma surface plasmons. SPV) is a kind of electron density wave propagating along the metal surface produced by the interaction of electrons and photons in free vibration on the metal surface. It has the characteristics of near field local enhancement and breaking through the diffraction limit and so on. It has become a research hotspot in recent years. Various SPP waveguides have been reported one after another. The structure can be divided into two types: metal-dielectric-metal-mimm) waveguide and dielectric-metal-dielectric-dielectric waveguide, in which the MIM waveguide structure is compared with the IMI type waveguide structure. It can realize subwavelength transmission, shorten the waveguide spacing and make it simple, which is beneficial to the realization of micro-nano photon integration. In this paper, the wavelength range from 400 nm to 2000 nm is in the range of 400 nm to 2 000 nm. The influence of waveguide geometry on the operating characteristics of MIM type surface plasma waveguide filter is studied. A narrow band filter based on MIM type surface plasma waveguide structure is proposed. Firstly, the transmission characteristics of MIM type surface plasma waveguide are analyzed by finite element method. The relation curves of mode effective refractive index and transmission length with the width of interlayer and excitation wavelength are obtained. The transmission characteristics of the surface plasmon waveguide filter with branches based on MIM structure are simulated. The results show that the transmissivity curve of the two-side branch waveguide structure has a wider stopband than that of the unilateral branch node, and the passing band and the edge of the stopband of the transmission curve will be steeper when the position of the bilateral branch node deviates. It is suitable for the design of band-stop filter. On the basis of this, two kinds of staggered branches are introduced to realize the surface plasma excitation narrowband filter based on MIM waveguide, and the transmissivity curve of the filter is calculated numerically. The results show that the length of branch can affect the central wavelength of stopband and passband, and the width of transmission peak can be pinched by the difference of branch length. This conclusion provides a valuable reference for the design of narrowband filter in photonic integrated circuit.
【学位授予单位】：南京邮电大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN713

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