Plasphonics : local hybridization of plasmons and phonons

Renaud Marty (1, 2) , Adnen Mlayah (2) , Arnaud Arbouet (3) , Christian Girard (4, 3) , Sudhiranjan Tripathy (5)

1 Loire Cher Indre Rivers Flood Forecasting Centre
2 CEMES - Centre d'élaboration de matériaux et d'études structurales
3 CEMES-NeO - Nano-Optique et Nanomatériaux pour l'optique
4 CEMES-GNS - Groupe NanoSciences
5 A*STAR - Agency for science, technology and research [Singapore]

We show that the interaction between localized surface plasmons sustained by a metallic nano-antenna and delocalized phonons lying at the surface of an heteropolar semiconductor can generate a new class of hybrid electromagnetic modes. These plasphonic modes are investigated using an analytical model completed by accurate Green dyadic numerical simulations. When surface plasmon and surface phonon frequencies match, the optical resonances exhibit a large Rabi splitting typical of strongly interacting two-level systems. Based on numerical simulations of the electric near-field maps, we investigate the nature of the plaphonic excitations. In particular, we point out a strong local field enhancement boosted by the phononic surface. This effect is interpreted in terms of light harvesting by the plasmonic antenna from the phononic surface. We thus introduce the concept of active phononic surfaces that may be exploited for far-infared optoelectronic devices and sensors.

Domaines: Optique [physics.optics]

Renaud Marty, Adnen Mlayah, Arnaud Arbouet, Christian Girard, Sudhiranjan Tripathy. Plasphonics : local hybridization of plasmons and phonons. Optics Express, 2013, 21 (4), pp.4551. ⟨10.1364/OE.21.004551⟩. ⟨hal-02159603⟩