基于圆角矩形结构的表面等离子体激元滤波器与光开关

Plasmonic Filter and Electro-Optical Switch Based on Rectangular Cavity with Two Half Circle Ends

提出并研究基于圆角矩形结构的表面等离子体激元带通滤波器,运用时域有限差分方法(Finite-Difference Time-Domain,FDTD)对滤波器的透过率特性进行模拟仿真.由于采用圆角矩形结构,滤波器的透过率在带宽不变的情况下被优化.通过改变圆角矩形谐振腔的圆角半径以及腔长,可以实现所需要的透过率光谱.在圆角矩形结构基础上提出1×2解复用器,通过将输出端2与谐振腔耦合处的波导增长120 nm,实现了抑制共振模作用.通过在滤波器的圆角矩形谐振腔中注入具有双折射效应的液晶Merck BL009,提出具有波长选择作用的光开关.结果表明,基于圆角矩形结构的等离子体激元滤波器在纳米光学器件中具有很好的应用前景.

An ultra-compact surface plasmon polaritons（ SPPs） band-pass filter based on a rectangular cavity with two half circle ends is proposed and numerically investigated. The transmission properties of the filter are simulated by the Finite-Difference Time-Domain（ FDTD） method. Attributed to the half circle ends,the transmittances can be optimized with the same band width. One can realize the required transmission spectra by adjusting the radius of the half circles and the length of the cavity. Moreover,with a section of waveguide added on the output waveguide at the bottom of the cavity,an 1 × 2 wavelength demultiplexer with the ability of inhibiting resonant mode is proposed. And by embedding the liquid crystal in the resonator,the lter can act as an electro-optical switch. These results show potential applications on nano-optical devices.