MIM表面等离子激元布拉格纳米微腔

MIM Surface Plasmonic Bragg Nano Micro-Cavity

构建了一种金属-绝缘体-金属(MIM)表面等离子体布拉格波导结构,绝缘层为一维布拉格光栅结构。在布拉格光栅结构中引入缺陷,形成布拉格纳米微腔。这种纳米微腔结构可以将光子能量很好地局域在微腔中,且在金属与绝缘层界面上光子能量最强。分析了MIM波导的色散特性,获得了谐振波长为1550 nm时微腔的结构参数。同时利用时域有限差分(FDTD)方法讨论了绝缘层布拉格光栅周期数、绝缘层厚度、微腔长度对微腔品质因子Q和模式体积V的影响。通过合理的选择这些参数可以提高微腔性能,使其具有极小的模式体积V和高的Q/V值,可实现光子局域化。

A new type of metal-insulator-metal （MIM） surface plasmonic Bragg waveguide structure is proposed, in which one-dimensional Bragg grating is used as the intermediate insulating layer and the defect layer is introduced to construct the Bragg micro-cavity. The photon energy is well confined in the micro-cavity and most of the photon energy is localized along the interface between the insulating layer and metal. The structure parameters can be obtained through the analysis of the dispersion characteristics at the resonant wavelength of 1550 nm. The influences on the quality factor and mode volume by the structural parameters are analyzed by the finite-difference-time-domain （FDTD） method, such as the period number, the insulator layer thickness and the cavity length. The simulation results show that the performance of the cavity can be improved with proper parameters. The surface plasmonic Bragg nano micro-cavity has ultra-small mode volume V and high Q/V, which can achieve effective photon localization.