Sun Jinhai, Liu Yong-Qiang, Li Jining, Zhang Xutao, Cai He, Zhu Xianli, Yin Hongcheng
National Key Laboratory of Scattering and Radiation, Beijing 100854, China.
Institute of Laser and Optoelectronics, School of Precision Instruments and Opto-Electronics Engineering, Tianjin University, Tianjin 300072, China.
Nanomaterials (Basel). 2023 Apr 5;13(7):1279. doi: 10.3390/nano13071279.
A terahertz flexible metamaterial quarter-wave plate (QWP) is designed and fabricated using polyimide as the substrate in this paper, with a 3 dB axial ratio bandwidth of 0.51 THz and high polarization conversion efficiency and transmittance. The effect of the incidence angle on the polarization conversion performance of the QWP is discussed by measuring the transmissions at multiple incidence angles. The blocking effect of this QWP combined with a polarizer on the backward reflection of terahertz waves is investigated by terahertz time-domain spectral transmission experiments. By adjusting the angle of the QWP and polarizer with respect to the incident light in the optical path, a blocking efficiency of 20 dB can be achieved at a 20° incidence angle, with a bandwidth of 0.25 THz, a maximum blocking efficiency of 58 dB at 1.73 THz, and an insertion loss of only 1.4 dB. Flexible terahertz metamaterial QWPs and polarizers can effectively block harmful reflected waves in terahertz communication and other systems. They have the advantages of a simple structure, ultra-thinness and flexibility, easy integration, no external magnetic field, and no low-temperature and other environmental requirements, thus having broad application prospects for terahertz on-chip integrated systems.
本文设计并制作了一种以聚酰亚胺为基底的太赫兹柔性超材料四分之一波片（QWP），其3 dB轴比带宽为0.51 THz，具有高偏振转换效率和透过率。通过测量多个入射角下的透射率，讨论了入射角对QWP偏振转换性能的影响。通过太赫兹时域光谱透射实验，研究了该QWP与偏振器组合对太赫兹波后向反射的阻挡效果。通过调整光路中QWP和偏振器相对于入射光的角度，在20°入射角下可实现20 dB的阻挡效率，带宽为0.25 THz，在1.73 THz处最大阻挡效率为58 dB，插入损耗仅为1.4 dB。柔性太赫兹超材料QWP和偏振器可有效阻挡太赫兹通信等系统中的有害反射波。它们具有结构简单、超薄且柔性、易于集成、无需外部磁场以及无低温等环境要求的优点，因此在太赫兹片上集成系统中具有广阔的应用前景。
