Gansel Justyna K, Wegener Martin, Burger Sven, Linden Stefan
Institut für Angewandte Physik and DFG-Center for Functional Nanostructures (CFN), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany.
Opt Express. 2010 Jan 18;18(2):1059-69. doi: 10.1364/OE.18.001059.
We have recently shown that metamaterials composed of three-dimensional gold helices periodically arranged on a square lattice can be used as compact "thin-film" circular polarizers with one octave bandwidth. The physics of the motif of these artificial crystals is closely related to that of microwave sub-wavelength helical antennas in end-fire geometry. Here, we systematically study the dependence of the metamaterial's chiral optical properties on helix pitch, helix radius, two-dimensional lattice constant, wire radius, number of helix pitches, and angle of incidence. Our numerical calculations show that the optical properties are governed by resonances of the individual helices, yet modified by interaction effects. Furthermore, our study shows possibilities and limitations regarding performance optimization.
我们最近表明，由周期性排列在正方形晶格上的三维金螺旋组成的超材料可用作具有一个倍频程带宽的紧凑型“薄膜”圆偏振器。这些人工晶体结构单元的物理原理与端射几何结构中的微波亚波长螺旋天线密切相关。在此，我们系统地研究了超材料的手性光学性质对螺旋间距、螺旋半径、二维晶格常数、线半径、螺旋节数和入射角的依赖性。我们的数值计算表明，光学性质由单个螺旋的共振决定，但会受到相互作用效应的影响。此外，我们的研究显示了性能优化方面的可能性和局限性。
