High-Order Hilbert Curves: Fractal Structures with Isotropic, Tailorable Optical Properties
High-Order Hilbert Curves: Fractal Structures with Isotropic, Tailorable Optical Properties
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DOI：
10.1021/acsphotonics.5b00363
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发表时间：
2015-12
期刊：
影响因子：
7
通讯作者：
S. D. Zuani;T. Reindl;Marcus Rommel;B. Gompf;A. Berrier;M. Dressel
中科院分区：
文献类型：
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作者：
S. D. Zuani;T. Reindl;Marcus Rommel;B. Gompf;A. Berrier;M. Dressel
©2015美国化学学会。分数维是一种具有均匀、各向同性和与频率无关的有效光学响应的非周期、非共振结构，具有很好的应用前景。在可见光和近红外光谱范围内，我们对N=9阶分形级金属希尔伯特曲线进行了全面的光学研究。实验表明，高阶分形纳米结构具有近乎频率无关的反射率和平面内各向同性的光学响应。这种响应可以在一个简单有效的介质近似模型的框架内用有限的参数来模拟。结果表明，高阶Hilbert结构可以看作是一种透明的面内金属，其介电函数可以通过填充因子f来修正，从而在不经历绝缘体到金属的转变的情况下产生具有可调等离子体频率和可变反射率的可调谐导电有效金属。
© 2015 American Chemical Society. Fractals are promising candidates as nonperiodic, nonresonant structures exhibiting a homogeneous, isotropic, and frequency-independent effective optical response. We present a comprehensive optical investigation of a metallic Hilbert curve of fractal order N = 9 in the visible and near-infrared spectral range. Our experiments show that high-order fractal nanostructures exhibit a nearly frequency independent reflectance and an in-plane isotropic optical response. The response can be simulated in the framework of a simple effective medium approximation model with a limited number of parameters. It is shown that high-order Hilbert structures can be considered as a transparent in-plane metal, the dielectric function of which is modified by the filling factor f, hence creating a tunable conductive effective metal with tailorable plasma frequency and variable reflectance without going through an insulator-to-metal transition.