Noble Metal Alloys for Plasmonics
Noble Metal Alloys for Plasmonics
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DOI：
10.1021/acsphotonics.5b00586
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发表时间：
2016-04-01
期刊：
影响因子：
7
通讯作者：
Leite, Marina S.
中科院分区：
文献类型：
--
作者：
Gong, Chen;Leite, Marina S.
贵金属的固定光学性质目前限制了它们在以光学频率操作的光子器件中的使用。为了获得具有可调谐光学响应的金属，我们提出了由Ag、Au和Cu的二元混合物形成的贵金属合金薄膜。由于合金的介电函数（epsilon）无法建模为纯金属的线性组合，因此我们将合金薄膜的透射和反射测量与考虑Kromers-Kronig关系的B样条模型结合起来，并通过实验确定介电函数。我们发现，在某些情况下，混合物可以提供具有比相应的纯金属更高的表面等离子体激元品质因子的材料。我们独立地测量了表面等离子体极化子耦合角的所有合金使用的Kretschmann配置，并发现两种方法之间的良好协议时，确定e。我们的方法为实现具有按需光学响应的金属薄膜和纳米结构铺平了道路，克服了贵金属介电函数的电流限制。
The fixed optical properties of noble metals currently limit their use in photonic devices that operate at optical frequencies. To achieve metals with tunable optical response, we present noble metal alloyed thin-films formed by the binary mixture of Ag, Au, and Cu. As the dielectric functions (epsilon) of the alloys cannot be modeled as the linear combination of the pure metals, we combined transmission and reflection measurements of the alloyed thin films with a B-spline model that takes into account the Kromers-Kronig relation and experimentally determined the dielectric functions. We found that in some cases a mixture can provide a material with higher surface plasmon polariton quality factor than the corresponding pure metals. We independently measured the surface plasmon polariton coupling angle for all alloys using the Kretschmann configuration and found excellent agreement between the two methods when determining e. Our approach paves the way to implement metallic thin films and nanostructures with on-demand optical responses, overcoming the current limitation of the dielectric function of noble metals.