Li Zhe-Wen, Li Jiu-Sheng
Appl Opt. 2021 Mar 10;60(8):2450-2454. doi: 10.1364/AO.419515.
A switchable metasurface with dual functions of polarization conversion and filtering is proposed in this paper. The designed structure is composed of a medium-metal-medium-metal-medium structure, and is embedded in the metal metasurface. When is an insulated state, this structure can perform linear polarization conversion under terahertz wave normal incidence, and it has good asymmetric transmission capabilities. At the range from 2.01 to 2.86 THz, the polarization conversion rate is higher than 93%. When is in the metallic state, the structure becomes a broadband band-stop filter with a 3 dB bandwidth of 1.73 THz. The polarization conversion and filtering functions of the proposed structure can be converted to each other by changing the external temperature. This switchable multifunction structure provides a new way for the design of terahertz devices.
本文提出了一种具有偏振转换和滤波双重功能的可切换超表面。所设计的结构由介质-金属-介质-金属-介质结构组成，并嵌入金属超表面中。当处于绝缘状态时，该结构在太赫兹波垂直入射下可实现线性偏振转换，且具有良好的非对称传输能力。在2.01至2.86太赫兹范围内，偏振转换率高于93%。当处于金属状态时，该结构成为一个3分贝带宽为1.73太赫兹的宽带带阻滤波器。通过改变外部温度，所提出结构的偏振转换和滤波功能可以相互转换。这种可切换的多功能结构为太赫兹器件的设计提供了一种新途径。
