Ionic terahertz metasurface in ultrathin-layered conductive hydrogel by ultrafast laser tailoring

作者：Tao, Yufeng^*; Wang, Bingjie; Xu, Weijie; Wang, Xuejiao; Ren, Yunpeng; Xin, Zhiduo; He, Kun; Ma, Xiangjun; He, Guangjian; Deng, Chunsan; Dai, Zijie^*

来源：Optics and Laser Technology, 2024, 170: 110252.

DOI：10.1016/j.optlastec.2023.110252

• Ionic hydrogel metasurfaces
• Terahertz
• Picosecond laser
• Dielectric properties

The ion-interactive semi-conductive hydrogel emerged as a promising optoelectronic material due to its desirable electrical conductivity, optical clarity, and switchable dielectric properties beyond incumbent inorganic mate-rials. However, developing the actively modulated terahertz (THz) devices via hydrogel remained barely studied at an early stage. Herein, a scalable high-throughput picosecond laser system rapidly tailored hydrogel into ion-interactive dielectric metasurfaces (IDMs). The IDMs exhibited minus permittivity (e < 0 F/m) not belonging to hydrogel, tunable time/frequency modulation, and high-consistency geometries for specific THz wave manip-ulations. The interplay between anions and the n-conjugated thiophene ring of hydrogel dynamically changed the dielectric properties and electrical conductivity through mixed electron/hole transportation, making IDMs change their microscale electric fields anomalously. Other as-prepared IDMs (split resonators, interleaved an-tennas, and their array) further confirmed the native capability of generating orbital angular momentum, spatially manipulating THz waves, or tuning frequencies. This work ushers in a new platform to customize and deploy non-metal THz meta devices in batches.

• 单位
  江苏大学; 华中科技大学