基于微腔耦合结构金属弯曲波导的光透射特性

Light Transmission Characteristics of Metal Curved Waveguide Based on Microcavity Coupling Structures

提出了一种基于微腔耦合结构的等离子体弯曲波导新型滤波器,该滤波器由两个直角波导和一个矩形谐振腔组成,光通过该结构会激发表面等离子体激元(SPPs)。采用时域有限差分(FDTD)法研究了此结构SPPs的传播特性。结果表明,相比于传统的直波导结构,由于其会引发双边耦合效应,这种单微腔弯曲波导结构产生了更强烈的共振作用,其耦合效率也得到了进一步的提高。数值仿真结果表明,通过改变谐振腔的腔长,也可达到线性调节滤波器共振波长的目的。此外,在上述设计思路的基础上还提出了一种双微腔结构,此结构由一个弯曲波导与左右两个谐振腔组成,其可利用两个微腔透射波的叠加作用,产生动态可调控的等离子诱导透明效应。

A novel plasma curved waveguide filter based on microcavity coupling structure is presented, which consists of two rectangular waveguide and a rectangular resonant cavity. When light passes through the structure, surface plasmon polaritons （SPPs） can be excited. The propagation properties of the SPPs with this structure are investigated by the finite difference time domain （FDTD） method. The results show that, compared with the traditional straight waveguide structure, the single microcavity curved waveguide structure can generate stronger resonant interaction and higher coupling effect for the bilateral coupling effect induced by the structure. The numerical simulation results show that the resonant wavelength of the filter can be adjusted linearly by changing the cavity length of the resonator. In addition, based on the above design idea, a dual microcavity structure is also proposed. The structure consists of a bent waveguide and two resonant cavities at left and right, which can be used to produce dynamically tunable plasma induced transparency by the superposition of two microcavity transmission waves.