Plexciton modes guided by an exciton slab in a columnar thin film

Abstract

In this study, we reported the plasmon-exciton coupling for excitation of the surface plexciton wave in columnar thin film with a central exciton slab using the transfer matrix method in Turbadar–Kretschmann–Raether configuration. The optical absorptance spectra for surface plasmon polariton, surface exciton and surface plexciton was investigated at different structural parameters in proposed structure. The characteristics of surface optical modes were analyzed and there was an anticrossing behavior between polariton branches of plexciton spectra. Localization of surface modes on interfaces and hybridization between plasmons and excitons at both interfaces of exciton slab were proved by the time-averaged Poynting vector. We found that the types of coupling regimes between plasmons and excitons from weak to strong could be achieved. We obtained a high Rabi splitting energy 840 meV corresponding to the time period 5 fs which indicates to the fast energy transfer between surface plasmon polaritons and surface excitons.