Arnold Matthew D, Blaber Martin G
Institute for Nanoscale Technology, Department of Physics and Applied Materials, University of Technology Sydney,PO Box 123 Broadway, NSW 2007, Australia.
Opt Express. 2009 Mar 2;17(5):3835-47. doi: 10.1364/oe.17.003835.
Optical metrics relating to metallic absorption in representative plasmonic systems are surveyed, with a view to developing heuristics for optimizing performance over a range of applications. We use the real part of the permittivity as the independent variable; consider strengths of particle resonances, resolving power of planar lenses, and guiding lengths of planar waveguides; and compare nearly-free-electron metals including Al, Cu, Ag, Au, Li, Na, and K. Whilst the imaginary part of metal permittivity has a strong damping effect, field distribution is equally important and thus factors including geometry, real permittivity and frequency must be considered when selecting a metal. Al performs well at low permittivities (e.g. sphere resonances, superlenses) whereas Au & Ag only perform well at very negative permittivities (shell and rod resonances, LRSPP). The alkali metals perform well overall but present engineering challenges.
我们研究了与代表性等离子体系统中金属吸收相关的光学指标，旨在开发启发式方法以优化一系列应用中的性能。我们将介电常数的实部用作自变量；考虑粒子共振强度、平面透镜的分辨能力和平面波导的导波长度；并比较包括铝、铜、银、金、锂、钠和钾在内的近自由电子金属。虽然金属介电常数的虚部具有很强的阻尼效应，但场分布同样重要，因此在选择金属时必须考虑包括几何形状、实介电常数和频率等因素。铝在低介电常数情况下表现良好（例如球体共振、超透镜），而金和银仅在非常负的介电常数情况下表现良好（壳层和棒状共振、长程表面等离激元极化激元）。碱金属总体表现良好，但存在工程挑战。
