Li Jing, Cai Rui, Chen Huanyang, Ma BinYi, Wu Qiannan, Li Mengwei
School of Instrument and Electronics, North University of China, Taiyuan, 030051, China.
Department of Physics, Xiamen University, Xiamen, 361000, China.
Sci Rep. 2024 Aug 27;14(1):19868. doi: 10.1038/s41598-024-69875-6.
Under the support of deep neural networks (DNN), a multifunctional switchable terahertz metamaterial (THz MMs) device is designed and optimized. This device not only achieves ideal ultra-wideband (UWB) absorption in the THz frequency range but enables dual-functional polarization transformation over UWB. When vanadium dioxide (VO) is in the metallic state, the device as a UWB absorber with an absorption rate exceeding 90% in the 2.43-10 THz range, with a relative bandwidth (RBW) of 145.2%, and its wideband absorption performance is insensitive to polarization. When VO is in the insulating state, the device can switch to a polarization converter, achieving conversions from linear to cross polarization and from linear to circular polarization in the ranges of 4.58-10 THz and 4.16-4.43 THz, respectively. Within the 4.58-10 THz range, the polarization conversion ratio approaches 100% with an RBW of 74.3%, the polarization rotation angle is near 90°. Within the 4.16-4.43 THz range, the RBW is 6.29% and the ellipticity ratio approaches 1, Moreover, the effects of incident angle and polarization angle on the operational characteristics are studied. This THz MMs due to its advantages of wide angle, broad bandwidth, and high efficiency, provides valuable references for the research of new multifunctional THz devices. It has great application potential in short-range wireless THz communication, ultrafast optical switches, high-temperature resistant switches, transient spectroscopy, and optical polarization control devices.
在深度神经网络（DNN）的支持下，设计并优化了一种多功能可切换太赫兹超材料（THz MMs）器件。该器件不仅在太赫兹频率范围内实现了理想的超宽带（UWB）吸收，还能在超宽带上实现双功能偏振转换。当二氧化钒（VO）处于金属态时，该器件作为一个超宽带吸收器，在2.43 - 10太赫兹范围内吸收率超过90%，相对带宽（RBW）为145.2%，其宽带吸收性能对偏振不敏感。当VO处于绝缘态时，该器件可切换为偏振转换器，分别在4.58 - 10太赫兹和4.16 - 4.43太赫兹范围内实现从线偏振到交叉偏振以及从线偏振到圆偏振的转换。在4.58 - 10太赫兹范围内，偏振转换率接近100%，相对带宽为74.3%，偏振旋转角接近90°。在4.16 - 4.43太赫兹范围内，相对带宽为6.29%，椭圆率接近1。此外，还研究了入射角和偏振角对其工作特性的影响。这种太赫兹超材料由于其广角、宽带宽和高效率的优点，为新型多功能太赫兹器件的研究提供了有价值的参考。它在短程无线太赫兹通信、超快光开关、耐高温开关、瞬态光谱学以及光偏振控制器件等方面具有巨大的应用潜力。
