设计一种偏振不敏感、制作简单的一维双频吸收器, 该吸收器一个周期阵列中采用垂直方向上级联四对金属介质层。仿真结果显示, 可以实现偏振不敏感的双频吸收, 其吸收原理是根据磁激元共振对TM偏振波吸收和波导模式共振对TE偏振波吸收, 通过LC等效电路和本征方程来预测结构参数, 以及对电磁场分布进行分析来进一步了解吸收器的吸波原理。更重要的是, 一维偏振不敏感结构的吸收器对TM、TE偏振波的吸收是独立的, 且临近的金属-介质之间的距离对波的吸收影响很小, 这样使设计更加自由、灵活, 制作更加简单, 灵活性高, 覆盖的电磁波范围增大, 可以延伸到微波频段和太赫兹频段。这样的一维偏振不敏感双频吸收器的研究对以后实现一维偏振不敏感宽带吸收器有很大的意义,它将会应用到很多设备当中去。

Based on a stacked array consisted of vertically cascaded four pairs of metal dielectric bilayers, a one-dimensional double-frequency absorber with polarization insensitive and fabrication-tolerant is designed. Simulation results show that the absorber can implement double-frequency polarization insensitive absorption based on the absorption principle of magnetic excitation resonance to TM polarization wave absorption and waveguide mode resonance to TE polarization wave absorption. Structure parameters are predicted through LC equivalent circuit and eigen equation, and the electromagnetic field distribution is analyzed to further understand the absorption principle of the absorber. More importantly, the insensitive structure of the one-dimensional absorber is independent for TM and TE polarization wave absorption, and the absorption characteristics of the absorber is less affected by the spacing distance between the neighboring stacks, which make more free and flexible in the design, make the absorber extremely simple in fabrication and have high flexibility, with covering the range of electromagnetic waves from microwave frequencies extended to terahertz. The research on the absorber is very important to the absorber development and it will have better application prospect.