Kowerdziej Rafał, Wróbel Jerzy, Kula Przemysław
Institute of Applied Physics, Military University of Technology, 2 Kaliskiego Str., 00-908, Warsaw, Poland.
Institute of Physics, Polish Academy of Sciences, 32/46 Lotników Avenue, 02-668, Warsaw, Poland.
Sci Rep. 2019 Dec 30;9(1):20367. doi: 10.1038/s41598-019-55656-z.
Shortening of switching times of various soft-matter-based tunable metamaterials is one of the key challenges to improve the functionality of modern active devices. Here we show an effective strategy in the evolution of soft-matter-based tunable metamaterials that makes possible acceleration of both on and off switching processes by using a dual-frequency liquid crystal mixture. The frequency-convertible dielectric anisotropy of the dual-frequency mixture enabled us to create a fast-response in-plane switching metasurface at the nanoscale, which could be tuned by an electrical signal with different frequencies. The results clearly show that the resonance of the metamaterial can be continuously and reversibly controlled within a wavelength range of 100 nm as the applied frequency is inverted between 1 kHz and 40 kHz, with a total response time (τ = τ + τ) of 1.89 ms. Furthermore, experimental characteristics of the hybrid metamaterial are in great agreement with numerical calculations, which allow us to anticipate active epsilon-near-zero behavior of the metadevice. This work indicates the future development direction of liquid-crystal-based active plasmonic systems.
缩短各种基于软物质的可调谐超材料的切换时间是提高现代有源器件功能的关键挑战之一。在此，我们展示了一种基于软物质的可调谐超材料的有效演化策略，通过使用双频液晶混合物，实现了开启和关闭切换过程的加速。双频混合物的频率可转换介电各向异性使我们能够在纳米尺度上创建一个快速响应的面内切换超表面，该超表面可以通过不同频率的电信号进行调谐。结果清楚地表明，当施加频率在1kHz和40kHz之间反转时，超材料的共振可以在100nm的波长范围内连续且可逆地控制，总响应时间（τ = τ + τ）为1.89ms。此外，混合超材料的实验特性与数值计算结果高度吻合，这使我们能够预测该超器件的有源近零介电常数行为。这项工作指明了基于液晶的有源等离子体系统的未来发展方向。
