Evaluation of effective electric permittivity and magnetic permeability in metamaterial slabs by terahertz time-domain spectroscopy.
Evaluation of effective electric permittivity and magnetic permeability in metamaterial slabs by terahertz time-domain spectroscopy.
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DOI：
10.1364/oe.16.004785
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发表时间：
2008-03
期刊：
影响因子：
3.8
通讯作者：
Y. Minowa;T. Fujii;M. Nagai;T. Ochiai;K. Sakoda;K. Hirao;Koichiro Tanaka
中科院分区：
文献类型：
--
作者：
Y. Minowa;T. Fujii;M. Nagai;T. Ochiai;K. Sakoda;K. Hirao;Koichiro Tanaka
建立了一种利用太赫兹时域光谱技术计算有效光学常数的新方法，并根据热力学第二定律给出了光学常数的严格定义和电磁能量损耗的表达式。从实验和理论上推导了磷青铜线栅在太赫兹波段的有效光学常数。结果强烈依赖于太赫兹波的偏振。当电场平行于导线时，我们观察到Drude样的电介电性，等离子体频率降低了10（-3）倍，而当电场垂直时，样品表现为简单的介电膜。我们还观察到意想不到的磁导率，这源于非共振真实的磁响应的有限尺寸导体。
We established a novel method to evaluate effective optical constants by terahertz (THz) time domain spectroscopy and suggested a strict definition of optical constants and an expression for electromagnetic energy loss following the second law of thermodynamics. We deduced the effective optical constants of phosphor bronze wire grids in the THz region experimentally and theoretically. The results depend strongly on the polarization of the THz waves. When the electric field is parallel to the wires, we observed Drude-like electric permittivities with a plasma frequency reduced by a factor of 10(-3), whereas when the field is perpendicular, the sample behaved as a simple dielectric film. We also observed unexpected magnetic permeabilities, which originate from the non-resonant real magnetic response of finite size-conductors.