We present an ultra-thin film absorber made of a metallic/dielectric (Ni/SiO2) metamaterial with a half cylinder cross section. The proposed structure exhibits high absorption for both polarization modes. The total average absorption is over 96% and 92% for transverse electric (TE) and transverse magnetic (TM) polarization, respectively, for normal incidence in all the visible spectrum. This property is well maintained over a wide range of angles of incidence from 0° to 80°. The effects of the structure periodicity are also investigated for both modes and the results show small changes for variations of the order of 200 nm. We also analyzed the structure for a different number of metal-dielectric pairs considering different layers thicknesses. The results show that the absorber can maintain an excellent absorption even with possible errors during the fabrication process. The proposed structure can be used for a wide range of applications, such as thermal emitters, thermophotovoltaics (TPV), optical energy harvesting, thermal detectors among others where a broadband absorption is required.

我们提出了一种由半圆柱横截面的金属/电介质（Ni / SiO2）超材料制成的超薄膜吸收器。所提出的结构对于两种偏振模式均表现出高吸收性。对于在所有可见光谱中的法线入射，横向电（TE）和横向磁（TM）极化的总平均吸收分别超过96％和92％。在从0°到80°的大入射角范围内都可以很好地保持此特性。还研究了两种模式的结构周期性的影响，结果表明，对于200 nm量级的变化，变化很小。考虑到不同的层厚，我们还分析了不同数量的金属-电介质对的结构。结果表明，即使在制造过程中可能存在误差，该吸收剂也可以保持优异的吸收。所提出的结构可用于广泛的应用，例如热发射器，热光电（TPV），光能收集，热检测器以及其他需要宽带吸收的应用。