Key Laboratory of Microgravity, Institute of Mechanics, Chinese Academy of Sciences, Beijing, 100190, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Sci Rep. 2018 Jan 30;8(1):1861. doi: 10.1038/s41598-018-19374-2.
We propose a single-phase super lens with a low density that can achieve focusing of sound beyond the diffraction limit. The super lens has a star-shaped lattice structure made of steel that offers abundant resonances to produce abnormal dispersive effects as determined by negative parameter indices. Our analysis of the metamaterial band structure suggests that these star-shaped metamaterials have double-negative index properties, that can mediate these effects for sound in water. Simulations verify the effective focusing of sound by a single-phase solid lens with a spatial resolution of approximately 0.39 λ. This superlens has a simple structure, low density and solid nature, which makes it more practical for application in water-based environments.
我们提出了一种具有低密度的单相超透镜，能够实现超越衍射极限的声波聚焦。该超透镜采用钢制成的星型晶格结构，具有丰富的共振，可产生由负参数指数决定的异常色散效应。我们对超材料能带结构的分析表明，这些星型超材料具有双负折射率特性，可在水中传播声音并产生这些效应。模拟验证了具有约 0.39λ 的空间分辨率的单相固体透镜对声波的有效聚焦。该超透镜具有结构简单、密度低和固态的特点，使其更适用于水基环境中的应用。
