Cui Xingshuo, Liu Dan, Wang Zanyang, Wang Dengpan, Wu Borui, Wang Guangming, Zheng Bin, Cai Tong
Air and Missile Defense College, Air Force Engineering University, Xi'an, 710051, China.
State Key Laboratory of Modern Optical Instrumentation, The Electromagnetics Academy Zhejiang University, Hangzhou, 310027, China.
Nanophotonics. 2022 Nov 24;12(1):119-127. doi: 10.1515/nanoph-2022-0578. eCollection 2023 Jan.
Achromatic devices present unique capabilities in efficient manipulation of waves and have wide applications in imaging and communication systems. However, the research of achromatic devices is limited by the narrow bandwidth, low efficiency as well as large configurations. In this paper, we propose a general strategy to design spin-locked achromatic metasurface with broadband and high efficiency properties in microwave region. A multi-resonant model is used to control the dispersion within a wide bandwidth by tuning its resonant intensity, resonance numbers as well as resonant frequency. As a proof of the concept, two achromatic meta-devices with ultra-thin profile at microwave frequency are experimentally investigated. The achromatic deflector can reflect the normal incident waves to the same angle within 9.5 to 11.5 GHz, while the other achromatic lens can focus the excitations at the same focal points. The experimentally working efficiency of the meta-devices fluctuates around 71-82% and 57-65% within the target working bandwidth, respectively. Moreover, our meta-devices can preserve the charity of the excitations. The scheme of this research shows great advances in the design of broadband and high-efficiency achromatic devices which can also be applied to other frequency ranges and inspires the realization of ultrabroadband and high-efficiency metadevices.
消色差器件在波的高效操控方面具有独特能力，在成像和通信系统中有广泛应用。然而，消色差器件的研究受到带宽窄、效率低以及结构庞大的限制。在本文中，我们提出一种通用策略，用于在微波频段设计具有宽带和高效特性的自旋锁定消色差超表面。采用多谐振模型，通过调整谐振强度、谐振数量以及谐振频率来控制宽频带内的色散。作为概念验证，对两种微波频率下具有超薄外形的消色差超器件进行了实验研究。消色差偏转器能在9.5至11.5吉赫兹范围内将垂直入射波反射到相同角度，而另一种消色差透镜能将激励聚焦到相同焦点。超器件在目标工作带宽内的实验工作效率分别在71% - 82%和57% - 65%左右波动。此外，我们的超器件能保持激励的特性。本研究方案在宽带和高效消色差器件设计方面取得了重大进展，这些器件也可应用于其他频率范围，并为实现超宽带和高效超器件提供了思路。
