设计了一种基于等离激元的具有对称双边耦合谐振腔的T形波分复用器, 与单边耦合的结构相比, 新结构由于对称谐振腔的相互耦合, 透射波振幅得到了加强, 因此系统的透射特性得到了一定的提升。对透射特性的分析采用模式耦合理论, 并且用有限元法(FEM)进行数值仿真。仿真结果表明, 此结构的各信道共振波长可通过改变结构的几何参数来调节, 同时对填充在谐振腔中的介质折射率有着较强的响应。两个端口处的透射峰波长分别为1310和1550nm, 透射率分别达到了67%和70%, 对于未来光通信和光子集成光路具有重要的参考价值。

A T-shaped plasmonic demultiplexer with symmetric dual side-coupled nanodisk resonators in metal-insulator-metal system was proposed. Compared with the single side-coupled nanodisk resonator structure, the new structure presents better transmission response due to the superposition of the outgoing-wave fields amplitudes of the two resonators. The accurate transmission expression was provided based on the temporal coupled mode theory, and the dynamic transmission response was studied with the finite element method (FEM). The demultiplexer wavelength can be easily manipulated by appropriately choosing the geometric size and the refractive index of the dielectric filled in the cavities. Moreover, the optimum transmission at two communication wavelengths of 1310 and 1550nm reaches up to 67% and 70%, respectively.