Jean-Claude Plenet

Emission of Tamm plasmon/exciton polaritons

We report on the observation of the strong coupling regime occurring between a Tamm plasmon (TP) mode and an exciton from inorganic quantum wells (QWs). The sample is formed by a silver thin film deposited onto an AlAs/GaAlAs Bragg reflector containing InGaAs QWs located in the high refractive index layers. Angular resolved reflectometry experiments evidence a clear anticrossing in the dispersion relations, a signature of the strong coupling regime. The Rabi splitting energy is 11.5 meV. The experimental data are in very good agreement with simple transfer matrix calculations. The emission from low and high energy TP/exciton polaritons is also demonstrated.

Iron-based 1D nanostructures by electrospinning process

Iron-based 1D nanostructures have been successfully prepared using an electrospinning technique and varying the pyrolysis atmospheres. Hematite (Fe(2)O(3)) nanotubes and polycrystalline Fe(3)C nanofibers were obtained by simple air or mixed gas (H(2), Ar) annealing treatments. Using the air annealing treatment, a high control of the morphology as well as of the wall thickness of the nanotubes was demonstrated with a direct influence of the starting polymer concentration. When mixed gases (H(2) and Ar) were used for the annealing treatments, for the first time polycrystalline Fe(3)C nanofibers composed of carbon graphitic planes were obtained, ensuring Fe(3)C nanoparticle stability and nanofiber cohesion. The morphology and structural properties of all these iron-based 1D nanostructures were fully characterized by SEM, TEM, XRD and Raman spectroscopy.

Polaritonic emission via surface plasmon cross coupling

In this letter the authors demonstrate that the emission of plasmon/exciton polaritons in an organic semiconductor can be extracted using surface plasmon cross coupling. A J-aggregated cyanine dye layer is deposited on a silver film and then the whole structure is periodically corrugated. As a result of this corrugation, the dispersion lines of the surface modes on both sides of the silver layer may cross. At this crossing point, an increase in the polaritonic emission is observed. The contributions of unpolarized incoherent states and of the TM polarized polaritons emission are separated.

Exciton/plasmon polaritons in GaAs/Al0.93Ga0.07As heterostructures near a metallic layer

We report on the strong coupling between inorganic quantum well excitons and surface plasmons. For that purpose a corrugated silver film was deposited on the top of a heterostructure consisting of GaAs/GaAlAs quantum wells. The formation of plasmon/heavy-hole exciton/light-hole exciton mixed states is demonstrated with reflectometry experiments. The interaction energies amount to 21 meV for the plasmon/light-hole exciton and 22 meV for the plasmon/heavy-hole exciton. Some particularities of the plasmon-exciton coupling were also discussed and qualitatively related to the plasmon polarization.

Optical properties of semiconductor in planar plasmonic structures: strong coupling and lasing

In this paper we describe the modifications in the GaAs quantum well (QW) optical properties induced by the proximity of a metallic film. The formation of hybrid plasmon/exciton states composed of a mix of heavy-hole exciton/light-hole exciton mixed states is demonstrated with reflectometry experiments. Alternative surface modes, namely Tamm plasmons, can also induce hybridization with the QW excitons with Rabi splitting energy of 11.5 meV. Plasmonic Tamm states are interface modes formed at the boundary between a photonic structure and a metallic layer. These modes present both the advantages of surface plasmons and of microcavities photonic modes. A conventional lasing effect will also be described in Tamm plasmon structure containing QWs. Tamm plasmons can be spatially confined by structuring the metallic part of the system, thus reducing the size of the mode and allowing various geometries. Due to the relatively low damping and the versatility of the Tamm geometries, these modes are good candidates for a new type of lasers.

Microcavities elaborated by sol-gel process

The fabrication and the optical properties of sol-gel high quality DBRs and microcavities are described and the emission of the europium ions included in the cavity observed. The microcavities are constituted of an SiO2 half wave Eu3+ doped active layer inserted between two sol-gel Bragg reflectors. These reflectors are formed by a stack of alternated quarter wave films of SiO2 and TiO2. Films were deposited by a dip coating method. To fabricate high quality Bragg mirrors, a large number of layers has to be stacked, but sol gel thin layers develop internal stresses during the drying and firing processes, leading to defects and cracks into the stacked films. The study of the stresses in the layers shows that a short 900°C layer annealing solves this problem and the number of stacked layers can be greater than 60 without cracks. A microcavity with 7 doublets Bragg mirrors has been fabricated using this process. Eu3+ luminescence modification due to the cavity effect, intensity enhancement and modification of the lineshape, has been observed, showing a cavity quality factor of 1200. The reflectivity factor of the associated Bragg mirrors reaches 99.8% for seven alternated SiO2/TiO2 layers.

Tamm surface plasmon laser

Plasmonic Tamm states are interface modes formed at the boundary between a photonic structure and a metallic layer. These modes present both the advantages of surface plasmons and of microcavities photonic modes. Tamm plasmons can be spatially confined by structuring the metallic part of the system, thus reducing the size of the mode and allowing various geometries. They are very good candidates for optimizing the emission properties of semiconductor nanostructures. Recently the extraction of single photons emitted by a quantum box has been evidenced in a Tamm Plasmon structure. Due to the relatively low damping and the versatility of the Tamm geometries, these modes are also good candidates for new type of lasers.

Exciton/plasmon polaritons in GaAs/GaAlAs heterostructures near a metallic layer

We report on the strong coupling between inorganic quantum well excitons and surface plasmons. For that purpose a corrugated silver film was deposited on the top of a heterostructure consisting of GaAs/GaAlAs quantum wells. The formation of plasmon/heavy-hole exciton/light-hole exciton mixed states is demonstrated with reflectometry experiments. The interaction energies amount to 21 meV for the plasmon/light-hole exciton and 22 meV for the plasmon/heavy-hole exciton. Some particularities of the plasmon-exciton coupling were also discussed and qualitatively related to the plasmon polarization.

Exciton/plasmon polaritons inGaAs/Al0.93Ga0.07Asheterostructures near a metallic layer

We report on the strong coupling between inorganic quantum well excitons and surface plasmons. For that purpose a corrugated silver film was deposited on the top of a heterostructure consisting of GaAs/GaAlAs quantum wells. The formation of plasmon/heavy-hole exciton/light-hole exciton mixed states is demonstrated with reflectometry experiments. The interaction energies amount to 21 meV for the plasmon/light-hole exciton and 22 meV for the plasmon/heavy-hole exciton. Some particularities of the plasmon-exciton coupling were also discussed and qualitatively related to the plasmon polarization.