Ma Zhikai, Fan Huiying, Zhou Hang, Huang Min, Luo Jie
Opt Express. 2021 Nov 22;29(24):39186-39199. doi: 10.1364/OE.443790.
Dynamically switchable light transmission/absorption functionality is highly desirable in sensing and functional devices. However, the operating bandwidth of the newly emerging schemes using resonant meta-structures is inherently limited. In this work, we design and numerically demonstrate a non-resonant tilted anisotropic metamaterial consisting of phase-change materials. When the phase transition of the phase-change material from amorphous phase to crystalline phase occurs, the functionality of the metamaterial can be switched from perfect transparency to perfect absorption for transverse-magnetic polarization under oblique incidence over a broad spectrum. Such a remarkable phenomenon originates in the anomalous Brewster effect, which enables broadband reflectionless transmission/absorption of light under the anomalous Brewster's angle. Moreover, gradient metamaterials exhibiting dynamically controllable functionality for incident light with an almost arbitrary wavefront are demonstrated. The proposed metamaterials are simple but highly efficient, which may find applications in sensing and advanced and intelligent optical devices.
在传感和功能器件中，动态可切换的光传输/吸收功能是非常理想的。然而，使用谐振超材料的新兴方案的工作带宽固有地受到限制。在这项工作中，我们设计并通过数值模拟证明了一种由相变材料组成的非谐振倾斜各向异性超材料。当相变材料从非晶相转变为晶相时，在斜入射下，该超材料对于横向磁极化的功能可以在宽光谱范围内从完全透明切换到完全吸收。这种显著的现象源于反常布儒斯特效应，该效应使得在反常布儒斯特角下能够实现光的宽带无反射传输/吸收。此外，还展示了对具有几乎任意波前的入射光表现出动态可控功能的梯度超材料。所提出的超材料简单但高效，可能在传感以及先进和智能光学器件中找到应用。
