Hu Yuze, Tong Mingyu, Hu Siyang, He Weibao, Cheng Xiang'ai, Jiang Tian
College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha 410073, P. R. China.
Beijing Institute for Advanced Study, National University of Defense Technology, Changsha 410073, P. R. China.
Nanophotonics. 2022 Feb 22;11(7):1367-1378. doi: 10.1515/nanoph-2021-0774. eCollection 2022 Mar.
The ability to actively manipulate free-space optical signals by using tunable metasurfaces is extremely appealing for many device applications. However, integrating photoactive semiconductors into terahertz metamaterials still suffers from a limited functionality. The ultrafast switching in picosecond timescale can only be operated at a single frequency channel. In the hybrid metasurface proposed here, we experimentally demonstrate a dual-optically tunable metaphotonic device for ultrafast terahertz switching at frequency-agile channels. Picosecond ultrafast photoswitching with a 100% modulation depth is realized at a controllable operational frequency of either 0.55 THz or 0.86 THz. The broadband frequency agility and ultrafast amplitude modulation are independently controlled by continuous wave light and femtosecond laser pulse, respectively. The frequency-selective, temporally tunable, and multidimensionally-driven features can empower active metamaterials in advanced multiplexing of information, dual-channel wireless communication, and several other related fields.
利用可调谐超表面主动操纵自由空间光信号的能力对许多器件应用极具吸引力。然而，将光活性半导体集成到太赫兹超材料中仍存在功能有限的问题。皮秒时间尺度内的超快开关只能在单个频率通道上运行。在此提出的混合超表面中，我们通过实验展示了一种用于在频率捷变通道进行超快太赫兹开关的双光学可调谐超光子器件。在0.55太赫兹或0.86太赫兹的可控工作频率下实现了具有100%调制深度的皮秒超快光开关。宽带频率捷变和超快幅度调制分别由连续波光和飞秒激光脉冲独立控制。频率选择性、时间可调性和多维驱动特性可以使有源超材料在先进的信息复用、双通道无线通信以及其他几个相关领域中发挥作用。
