Abstract
In classical Kretschmann-Raether configuration, the minimum appearing in reflectance is conventionally attributed to the resonance on a surface plasmon polariton of the metal/dielectric interface. The hypothesis about resonance on the subsystem plasmon polariton arises from the theory of eigenwave coupling in two adjoining domains. In this contribution, the theory of coupled eigenwaves is revised and tested for accuracy. It is revealed to have quite strong inherent limitations for thin metal films. This fact puts the hypothesis about coupling of a laser beam to the surface plasmon polariton in Kretschmann-Raether configuration in doubt. The doubt is further confirmed with the analysis of reflectance performed for the resonant eigenwave number. It demonstrates that the incident light resonates not on the subsystem surface plasmon polariton, but on the incoming polariton of the whole system. Detailed consideration of the system eigenwaves reveals three distinct regimes of Kretschmann-Raether configuration, where the incident light resonates on different types of incoming plasmon polaritons. Among them, the regime of coupling to transmission unguided plasmon polaritons provides the most powerful interaction with up to 100% efficiency.
- Received 5 June 2017
- Revised 27 September 2017
DOI:https://doi.org/10.1103/PhysRevB.96.155433
©2017 American Physical Society