一种带有支节的MIM型表面等离子体T型分束器

A MIM Surface Plasmon T-splitter Based on a Stub Structure

基于金属-电介质-金属结构,提出了一种带有支节的表面等离子体T型分束器,采用有限时域差分法研究其透射率与结构参量之间的关系.计算结果表明:改变T型波导中支节的宽度和长度,输出波导表面等离子体功率周期性变化;改变支节在T型波导支路中的纵向位置,金属-电介质-金属波导中表面等离子体分束比周期性变化;当分束比达到最大(或最小)时,T型分束器实现表面等离子体的定向传播.此外,采用表面等离子体干涉理论解释了分束比呈周期性变化的原因.

A T-shaped splitter of the surface plasmon wavegmde with a stub basea on metal-insulator- metal structure was proposed. The relationship between transmission and structure parameters was investigated by Finite-difference time-domain method. The simulation results show that the periodical changes of surface plasmons power can be achieved by changing the width and length of stub structure in T-shaped waveguide. Also, the periodical changes of splitting ratio for changes of surface plasmons can he obtained by changing the stub structure position of the output port in the metal-insulator-me waveguide structure. When the splitting ratio get maximum （or minimum）, T-shaped splitter can achieve the unidirectional propagation of changes of surface plasmons. Besides, the periodical changes of splitting ratio was explained based on the changes of surface plasmons interference theory.