在可见光到近红外频段，利用时域有限差分数值模拟计算方法，研究了一种多圆环形金属-介质-金属等离子体波导结构的电磁传输特性.结果表明，由于谐振作用，不同波长电磁波能量被分别束缚于圆环中，之后被耦合到各出口端进行传输，从而实现了电磁波的多路分频传输功能.圆环的共振波长与圆环半径之间存在近似线性关系，且随着圆环内填充介质折射率的增大呈现明显的红移现象；各出口端共振波长对应电磁能量的传输率随着介质波导与圆环间耦合厚度的增大而急剧降低.利用电磁波共振理论阐述了电磁能量的谐振束缚现象，与数值模拟结果吻合.研究结果可应用于未来光子集成器件中.

A multiple-ring shaped Metal-Insulator-Metal (MIM) plasmonic waveguide with multi-output ports was proposed. From visible lightto nearinfrared wavelengths, the transmission characteristics of the structure were investigated by finite-difference time-domain method. The structure exhibits typical wavelength demultiplexing function, which is due to that the electromagnetic wave energy of different wavelengths can be trapped in different insulator rings and coupled into the corresponding output ports. The resonance theory is employed to analyze the trapping phenomenon.The resonant wavelength of the ring has near linear relationship with the radius and has red shift with increase the value of the filled refractive index. The transmittance of resonant wavelength in the output ports are heavily influenced by the coupled thickness. The proposed multiple-ring shaped MIM waveguide may be useful for plasmonic designs.