Publications (10)0 Total impact
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Article: Selective photoexcitation of exciton-polariton vortices
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ABSTRACT: We resonantly excite exciton-polariton states confined in cylindrical traps. Using a homodyne detection setup, we are able to image the phase and amplitude of the confined polariton states. We evidence the excitation of vortex states, carrying an integer angular orbital momentum m, analogous to the transverse TEM01* "donut" mode of cylindrically symmetric optical resonators. Tuning the excitation conditions allows us to select the charge of the vortex. In this way, the injection of singly charged (m = 1 & m = -1) and doubly charged (m = 2) polariton vortices is shown. This work demonstrates the potential of in-plane confinement coupled with selective excitation for the topological tailoring of polariton wavefunctions.01/2010; -
Article: Hydrodynamic nucleation of quantized vortex pairs in a polariton quantum fluid
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Article: Dynamics of Long-Range Ordering in an Exciton-Polariton Condensate
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ABSTRACT: We report on time-resolved measurements of the first order spatial coherence in an exciton-polariton Bose-Einstein condensate. Long-range spatial coherence is found to set in right at the onset of stimulated scattering, on a picosecond time scale. The coherence reaches its maximum value after the population and decays slowly, staying up to a few hundred picoseconds. This behavior can be qualitatively reproduced, using a stochastic classical field model describing interaction between the polariton condensate and the exciton reservoir within a disordered potential. ©2009 The American Physical Society -
Article: Selective photoexcitation of confined exciton-polariton vortices
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ABSTRACT: We resonantly excite exciton-polariton states confined in cylindrical traps. Using a homodyne detection setup, we are able to image the phase and amplitude of the confined polariton states. We evidence the excitation of vortex states, carrying an integer angular orbital momentum m, analogous to the transverse TEM01∗ “donut” mode of cylindrically symmetric optical resonators. Tuning the excitation conditions allows us to select the charge of the vortex. In this way, the injection of singly charged (m=1 and m=−1) and doubly charged (m=2) polariton vortices is shown. This work demonstrates the potential of in-plane confinement coupled with selective excitation for the topological tailoring of polariton wave functions. -
Article: Phase-resolved imaging of confined exciton-polariton wave functions in elliptical traps
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ABSTRACT: We study the wave functions of exciton polaritons trapped in the elliptical traps of a patterned microcavity. A homodyne detection setup with numerical off-axis filtering allows us to retrieve the amplitude and the phase of the wave functions. Doublet states are observed as the result of the ellipticity of the confinement potential and are successfully compared to even and odd solutions of Mathieu equations. We also show how superpositions of odd and even states can be used to produce "donut" and "eight-shape" states which can be interpreted as polariton vortices. -
Article: Probability density tomography of microcavity polaritons confined in cylindrical traps of various sizes
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ABSTRACT: We present the optical tomography of the probability density of microcavity polaritons, confined in three dimensions by cylindrical traps of various sizes. Collecting the photoluminescence emitted by the quasimodes under continuous nonresonant laser excitation, we reconstruct a three dimensional mapping of the photoluminescence, from which we can extract the spatial distribution of the confined states at any energy. We discuss the impact of the confinement shape and size on the probability density patterns.Superlattices and Microstructures. -
Article: Resonant nonlinear studies of trapped 0D-microcavity polaritons
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ABSTRACT: We performed studies on microcavity polaritons trapped along the three dimensions of space, under resonant excitation on a confined lower polariton state. We observed various nonlinear behaviors as a function of the pump power, without any apparent loss of the strong-coupling. That may be understood as effects of Coulomb interaction. Indications of bistable behaviors in the system are observed and discussed. -
Article: Zero dimensional exciton-polaritons
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ABSTRACT: We present a novel semiconductor structure in which 0D polaritons coexist with 2D microcavity polaritons. Spatial trapping of the 2D microcavity polaritons results from the confinement of their photonic part in a potential well, consisting of an adjustable thickness variation of the spacer layer. This original technique allows to create polaritonic boxes of any size and shape. Strong coupling regime is evidenced by the typical energy level anticrossing, in real space and in momentum space, and supported by a theoretical model. -
Article: Nonlinear relaxation of zero-dimension-trapped microcavity polaritons
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ABSTRACT: We study the emission properties of confined polariton states in shallow zero-dimensional traps under nonresonant excitation. We evidence several relaxation regimes. For slightly negative photon-exciton detuning, we observe a nonlinear increase of the emission intensity, characteristic of carrier-carrier scattering assisted relaxation under strong-coupling regime. This demonstrates the efficient relaxation toward a confined state of the system. For slightly positive detuning, we observe the transition from strong to weak coupling regime and then to single-mode lasing. -
Article: Probability density optical tomography of confined quasiparticles in a semiconductor microcavity
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ABSTRACT: We present the optical tomography of the probability density of quasiparticles, the microcavity polaritons, confined in three dimensions by cylindrical traps. Collecting the photoluminescence emitted by the quasimodes under continuous nonresonant laser excitation, we reconstruct a three-dimensional mapping of the photoluminescence, from which we can extract the spatial distribution of the confined states at any energy. We discuss the impact of the confinement geometry on the wave function patterns and give an intuitive understanding in terms of a light-matter quasiparticle confined in a box.
