Grating couplers for surface plasmons excited on thin metal films in the Kretschmann-Raether configuration
Grating couplers for surface plasmons excited on thin metal films in the Kretschmann-Raether configuration
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DOI：
10.1103/physrevb.60.4992
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发表时间：
1999-08
影响因子：
3.7
通讯作者：
U. Schröter;D. Heitmann
中科院分区：
文献类型：
--
作者：
U. Schröter;D. Heitmann
我们研究了周期性调制的金属薄膜在Kretschmann-Raether组态中的光学性质。我们发现，通过光栅耦合器效应在金属表面不面对入射光的表面等离子体激元的激发是不可能的情况下的两个金属表面的共形调制，但只有当金属膜的厚度是在光栅周期变化。在这种情况下，两个表面上的表面等离子体之间存在强相互作用，并且光子带隙在色散中打开。而在反射光谱中，表面等离子体被视为最小值，它们可以出现在透射光谱中的最大值，最小值或Fano型共振。我们展示了如何薄膜光栅耦合器可以定制，以实现在特定的接口或明显的光子带隙的场强增强。
We investigate the optical properties of periodically modulated thin metal films in the Kretschmann-Raether configuration. We find that excitation of surface plasmons via the grating coupler effect at the metal surface not facing the incoming light is not possible in the case of a conformal modulation of the two metal surfaces, but only if the thickness of the metal film is varied over the grating period. In this case there is strong interaction between the surface plasmons on both surfaces and photonic band gaps open up in the dispersion. Whereas in reflection spectra the surface plasmons are seen as minima, they can appear as maxima, minima, or Fano-type resonances in transmission spectra. We show how thin film grating couplers can be tailored to achieve a field strength enhancement at a particular interface or pronounced photonic band gaps.