Broadband spontaneous emission rate enhancement through the design of plasmonic nanoantennas

We numerically investigate and experimentally demonstrate a new route to controllably manipulate the spontaneous decay rate of dipole emitters in coupled plasmonic modes. The structure under investigation is an hexagonal close-packed array of gold core - silica shell nanoparticles (NPs) sandwiched between two gold films. We show that the interaction of localized and propagating surface plasmon polaritons can dramatically enhance the spontaneous emission rate of quantum emitters (rhodamine isothiocyanate) grafted in the NP silica shell. This strong enhancement (70−100 times) further occurs on the whole, broadband emission spectrum (565 nm to 640 nm) of the emitters

Plasmonic opals: observation of a collective molecular exciton mode beyond the strong coupling

International audienceAchieving and controlling strong light-matter interactions in many-body systems is of paramount importance both for fundamental understanding and potential applications. In this paper we demonstrate both experimentally and theoretically how to manipulate strong coupling between the Bragg-plasmon mode supported by an organo-metallic array and molecular excitons in the formof J-aggregates dispersed on the hybrid structure. We observe experimentally the transition from a conventional strong coupling regime exhibiting the usual upper and lower polaritonic branches to a more complex regime, where a third nondispersive mode is seen, as the concentration of J-aggregates is increased. The numerical simulations confirm the presence of the third resonance. We attribute its physical nature to collective molecule-molecule interactions leading to a collective electromagneticresponse. A simple analytical model is proposed to explain the physics of the third mode. The nonlinear dependence on molecular parameters followed from the model are confirmed in a set of rigorous numerical studies. It is shown that at the energy of the collective mode molecules oscillate completely out of phase with the incident radiation acting as an effictive thin metal layer

Photon transport in cylindrically-shaped disordered meso-macroporous materials

We theoretically and experimentally investigate light diffusion in disordered meso-macroporous materials with a cylindrical shape. High Internal Phase Emulsion (HIPE)-based silica foam samples, exhibiting a polydisperse pore-size distribution centered around 19 μm to resemble certain biological tissues, are realized. To quantify the effect of a finite lateral size on measurable quantities, an analytical model for diffusion in finite cylinders is developed and validated by Monte Carlo random walk simulations. Steady-state and time-resolved transmission experiments are performed and the transport parameters (transport mean free path and material absorption length) are successfully retrieved from fits of the experimental curves with the proposed model. This study reveals that scattering losses on the lateral sides of the samples are responsible for a lowering of the transmission signal and a shortening of the photon lifetime, similar in experimental observables to the effect of material absorption. The recognition of this geometrical effect is essential since its wrong attribution to material absorption could be detrimental in various applications, such as biological tissue diagnosis or conversion efficiency in dye-sensitized solar cells

Propagation and survival of frequency-bin entangled photons in metallic nanostructures

We report on the design of two plasmonic nanostructures and the propagation of frequency-bin entangled photons through them. The experimental findings clearly show the robustness of frequency-bin entanglement, which survives after interactions with both a hybrid plasmo-photonic structure, and a nano-pillar array. These results confirm that quantum states can be encoded into the collective motion of a many-body electronic system without demolishing their quantum nature, and pave the way towards applications of plasmonic structures in quantum information

Propagation and survival of frequency-bin entangled photons in metallic nanostructures

We report on the design of two plasmonic nanos-tructures and the propagation of frequency-bin entangled photons through them. The experimental findings clearly show the robustness of frequency-bin entangle-ment, which survives after interactions with both a hybrid plasmo-photonic structure, and a nano-pillar array. These results confirm that quantum states can be encoded into the collective motion of a many-body electronic system without demolishing their quantum nature, and pave the way towards applications of plasmonic structures in quantum information

Structuration 3D des propriétés de luminescence au sein de verres inorganiques par inscription laser femtoseconde

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