Max Planck Institute for Intelligent Systems, Heisenbergstrasse 3, 70569 Stuttgart, Germany.
ACS Nano. 2011 Aug 23;5(8):6701-6. doi: 10.1021/nn2022414. Epub 2011 Jul 22.
By energy-filtering transmission electron microscopy (EFTEM), we observe Fabry-Pérot-like surface plasmon resonances (SPRs) along the length of rectangular single and double slits drilled into free-standing thin silver films. These eigenmodes hybridize in closely situated slits. The nature of their lateral coupling is uncovered from finite-element simulations, which show that the symmetry and energy sequence of hybrid modes is governed by Babinet complementarity principles. Interestingly, the modes of a double slit system, being proto-self-complementary, may alternatively be explained by magnetic interactions between slit fields or by electrostatic interactions across the metallic bridge separating the slits.
通过能量过滤透射电子显微镜（EFTEM），我们观察到沿矩形单狭缝和双狭缝的长度出现 Fabry-Pérot 型表面等离激元共振（SPR），这些狭缝是在独立的薄银膜上钻出的。这些本征模式在相邻狭缝中发生混合。有限元模拟揭示了它们横向耦合的性质，表明混合模式的对称性和能量序列受 Babinet 互补原理支配。有趣的是，双狭缝系统的模式是原始自互补的，也可以通过狭缝之间的金属桥的静电相互作用或狭缝场之间的磁相互作用来解释。
