Coupling of Surface-Plasmon-Polariton-Hybridized Cavity Modes between Submicron Slits in a Thin Gold Film
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- 作者：Roman Walther ; Stefan Fritz ; Erich Müller ; Reinhard Schneider ; Dagmar Gerthsen ; Wilfried Sigle ; Tsofar Maniv ; Hagai Cohen ; Christian Matyssek ; Kurt Busch
- 刊名：ACS Photonics
- 出版年：2016
- 出版时间：May 18, 2016
- 年：2016
- 卷：3
- 期：5
- 页码：836-843
- 全文大小：615K
- 年卷期：0
- ISSN：2330-4022
文摘
Electron energy loss spectroscopy (EELS) in a monochromated transmission electron microscope is applied to probe standing-wave-like cavity modes hybridized with surface plasmon polaritons (SPP) in rectangular submicron slits in a thin gold film. Coupling of hybridized SPP-cavity modes between two adjacent slits is studied by systematically varying the width of the metal bar d that separates the identical slits in a two-slit system. Measurements on two-slit systems with different slit lengths L and fixed width reveal energy shifts and mode splitting of the fundamental SPP cavity mode which can be generally described as a function of a dimensionless scaling parameter L/d. Numerical simulations with the Discontinuous Galerkin Time-Domain (DGTD) method confirm the experimental data and reveal insights into the underlying complex coupling mechanisms.