论文标题
超宽带反射的无反射Brewster吸收器受互惠保护
Ultra-broadband reflectionless Brewster absorber protected by reciprocity
论文作者
论文摘要
布鲁斯特定律预测，介电表面上的p极化的零反射在特定角度。但是，当将损耗引入介电介电常数中时，布鲁斯特的条件会分解并不可避免地反射。在这项工作中，我们通过创建一类非磁性各向异性的超材料来发现这一长期存在的困境，其中出现了具有独立可调的吸收和折射的异常Brewster效应。这种与损失无关的布鲁斯特效应受到各向异性引入的自由程度并严格受到互惠原理的保护。从DC到光学频率，带宽可以覆盖极宽的光谱。证明具有不同BREWSTER角度的无反射Brewster吸收器的两个例子都证明可以通过微波实验在广泛的范围内实现较大的吸光度。我们的工作将Brewster效应的范围扩展到非磁吸收材料的地平线，该材料有望以高效率以无反射吸收为前所未有的宽带宽。
The Brewster's law predicts zero reflection of p-polarization on a dielectric surface at a particular angle. However, when loss is introduced into the permittivity of the dielectric, the Brewster condition breaks down and reflection unavoidably appears. In this work, we found an exception to this long-standing dilemma by creating a class of nonmagnetic anisotropic metamaterials, where an anomalous Brewster effects with independently tunable absorption and refraction emerges. This loss-independent Brewster effect is bestowed by the extra degrees of freedoms introduced by anisotropy and strictly protected by the reciprocity principle. The bandwidth can cover an extremely wide spectrum from dc to optical frequencies. Two examples of reflectionless Brewster absorbers with different Brewster angles are both demonstrated to achieve large absorbance in a wide spectrum via microwave experiments. Our work extends the scope of Brewster effect to the horizon of nonmagnetic absorptive materials, which promises an unprecedented wide bandwidth for reflectionless absorption with high efficiency.
