Wei Xiuli, Wang Yongge, Yao Jingfeng, Li Jianfei, Yuan Chengxun, Zhou Zhongxiang
Opt Express. 2025 Jun 16;33(12):26857-26868. doi: 10.1364/OE.567025.
Conventional wave absorbers face challenges concerning their volumes and limited absorption efficiency. While metasurface-based absorbers have achieved breakthroughs in thickness reduction and absorption enhancement, their narrowband characteristics restrict broader applications. In this study, inspired by geometric involute, a metasurface structure, which can generate multiple localized surface plasmon resonances (LSPR) at different frequencies within a single unit for broadening the absorption bandwidth, is proposed. Simulations and experiments are conducted, demonstrating that the proposed design can reach an absorption bandwidth of 20-28.2 GHz with an efficiency greater than 10 dB and a thickness of only 1.67 mm (approximately one-ninth of the wavelength at the lowest operating frequency). Thus, it exhibits ultrathin characteristics. A further analysis shows that the metasurface maintains a stable absorption performance for polarization and incident angles, with an absorption of almost 10 dB for polarization angle changes of less than 50°, or for incidence angles of almost 60°. This provides what we believe to be a novel solution for the design of broadband absorbers.
传统的波吸收器在体积和有限的吸收效率方面面临挑战。虽然基于超表面的吸收器在厚度减小和吸收增强方面取得了突破，但其窄带特性限制了更广泛的应用。在本研究中，受几何渐开线的启发，提出了一种超表面结构，该结构可以在单个单元内的不同频率处产生多个局域表面等离子体共振（LSPR），以拓宽吸收带宽。进行了模拟和实验，结果表明，所提出的设计能够实现20 - 28.2 GHz的吸收带宽，效率大于10 dB，厚度仅为1.67 mm（约为最低工作频率波长的九分之一）。因此，它具有超薄特性。进一步分析表明，该超表面对于偏振和入射角保持稳定的吸收性能，对于小于50°的偏振角变化或近60°的入射角，吸收几乎为10 dB。这为宽带吸收器的设计提供了一种我们认为新颖的解决方案。
