Energy exchange between surface plasmon polaritons and CdSe/ZnS quantum dots

Evidence is presented for energy exchange between surface plasmon polaritons (SPPs) excited in waveguide-coupled Ag/Si3N4/Au structures and CdSe/ZnS quantum dot (QD) emitters. The QD dispersion is coated on the surface of Ag/Si3N4/Au nanostructure, surface plasmon resonance (SPR) is excited on surface of multilayered structure and the photoluminescence (PL) emission by the QDs is monitored as a function of the evanescent electric field by using fixed-detector pump-probe spectroscopy. We observe relatively large shift in the PL emission wavelength (corresponding to 4-5 meV) with accompanying electric field induced quenching (up to 50%) of the emission. Under the influence of the evanescent field, the PL emission peak splits into two components corresponding to two frequencies (Rabi splitting). Computer simulations are used to understand conditions under which Rabi splitting should occur.