Benoît Marie Joseph Deveaud

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We present a theoretical analysis of experimental photoluminescence spectra in highly excited semiconductor quantum wires. We show that the inclusion in the theory of electron-hole correlations strongly modifies the shape of emission spectra at any density. We discuss the role of these correlations in the evaluation of the band gap renormalization. The calculated energy- and density-dependence of the broadening agree qualitatively with the experimental results. The broadening is also comparable in magnitude

We have demonstrated ultrafast coherent control of excitons and exciton-polaritons in semiconductor quantum nanostructures. An InGaAs/AlGaAs multi-quantum-well Bragg structure and an AlGaAs/GaAs crescent-shaped quantum wire structure were used as samples for the control of the exciton-polariton and excitons in the nanostructure. In the multi-quantum-well Bragg sample, a two-stage decay due to the super-radiant exciton-polariton mode is clearly observed under the resonance conditions. Highly sensitive cohere

We present a theoretical model of the time-resolved excitonic photoluminescence in quantum wires. We study the role of disorder and of the exciton-free-carrier interaction on the temperature dependence of the photoluminescence lifetime. We find that at low temperature the exciton population is not thermalized in disordered quantum wires and that the lifetime is mainly determined by the localization length of the exciton. However, for large localization lengths or high enough temperatures the exciton populat

Using time-resolved photoluminescence, we have investigated the radiative behavior of neutral and negatively charged excitons in CdTe-based quantum wells. We find that the photoluminescence of negatively charged excitons can be well reproduced by a model of delocalized and thermalized three-particle complexes. A large radiative zone in k-space results from the transfer of the charged exciton momentum to the remaining electron (recoil effect). On the other hand, the photoluminescence decay of excitons is not

We report on the direct observation of biexcitons in a III-nitride based multiple quantum well microcavity operating in the strong light-matter coupling regime by means of nonresonant continuous wave and time-resolved photoluminescence at low temperature. ...

We study the dynamics of the charged and neutral excitons in a modulation-doped GaAs quantum well by time-resolved photoluminescence under a resonant excitation. The radiative lifetime of the charged exciton is found to be surprisingly short, 60 ps. This time is temperature independent between 2 and 10 K, and increases by a factor of 2 at 6 T. We discuss our findings in view of present theories of exciton radiative decay. [S0163-1829(98)03143-9].

Spectroscopy basically consists in retrieving information on any system through the use of optical information as a function of wavelength. The examples are countless, and the field is of major importance. For example, the structure of the hydrogen atom ha ...

We present the results of a detailed time-resolved luminescence study carried out on a very high quality InGaAs quantum well sample where the contributions at the energy of the exciton and at the band edge can be clearly separated. We perform this experiment with a spectral resolution and a sensitivity of the setup, allowing us to keep the observation of these two separate contributions over a broad range of times and densities. This allows us to directly evidence the exciton formation time, which depends o

Second-order time correlation measurements with a temporal resolution better than 3 ps were performed on a CdTe microcavity where spontaneous Bose-Einstein condensation is observed. After the laser pulse, the nonresonantly excited thermal polariton populat ...

We present femtosecond gain measurements in microcavity-embedded quantum wells. When the excitonic transition is saturated by an intense pump field, the spectrum measured with a weak probe pulse is strongly modulated by pump-probe wave mixing processes. A giant probe amplification occurs within the bandwidth of the empty-cavity mode. The optical feedback provided by the microcavity is responsible for a net gain of the broadband probe pulse. [S0163-1829(99)50424-4].

We report on the experimental observation of excitonic molecules (biexcitons) in high-quality V-shaped quantum wires. By means of spatially resolved near-field photoluminescence spectroscopy, first we unambiguously isolate excitons with a one-dimensional character, and secondly we present the optical transition from 1D biexciton to 1D exciton as a function of excitation power density. The density of these biexcitonic molecules is shown to increase superlinearly compared to the linear variation of exciton de

The Rayleigh scattering of light at resonance with the ground state exciton transition in quantum wells is studied by means of a microscopic model. The disorder-induced localization of the exciton center-of-mass leads to characteristic features of the scattered intensity which can help understanding the outcome of secondary emission experiments. In particular, the connection between time-resolved scattering and energy-level statistics, and the enhancement of the backscattered intensity in angle-resolved mea

We report on time-resolved photoluminescence studies of charged and neutral excitons in a modulation doped GaAs quantum well under resonant excitation and high magnetic field. The radiative lifetime of the charged exciton is rather short, 60 ps at zero held, and is found to increase by a factor of similar to 2 up to 7 T. The short lifetimes suggest that, under magnetic field, the exciton bound in the trion is delocalized. (C) 1998 Elsevier Science B.V. All rights reserved.

The formation dynamics of charged excitons is studied in CdTe-based quantum wells by picosecond time-resolved photoluminescence. The formation time is obtained by an analysis of temporal behavior of photoluminescence signal after excitation in resonance with either neutral or charged exciton. It is shown that the formation time varies strongly when changing the electron concentration. We also demonstrate that the localization of neutral excitons has strong impact on the formation time of charged exciton and

GaAs/GaAlAs quantum wires grown by modulated flow rate metalorganic chemical vapour deposition were investigated by spatially resolved photoluminescence spectroscopy using a scanning near-field optical microscope. It was found that the wires decompose into a series of regions that emit luminescence of varying intensity. The spectra of these regions feature several narrow emission lines, which means that there is a series of more or less localised exciton states inside each region. It is expected that these

We have investigated the ultrafast coherent dynamics of exciton-polaritons and excitons in semiconductor quantum nanostructures, including InGaAs/AlGaAs multi quantum well Bragg structures and AlGaAs/GaAs crescent shaped quantum wire samples, by using a phase-locked spectroscopic technique. In the multi quantum well Bragg sample, a two-stage decay due to the superradiant exciton-polariton mode is clearly observed at the resonant condition. In the crescent shaped quantum wire sample, the highly sensitive coh

We investigate the dynamics of donor bound excitons (D degrees X-A) at T = 10K around an isolated single edge dislocation in homoepitaxial GaN, using a picosecond time-resolved cathodoluminescence (TR-CL) setup with high temporal and spatial resolutions. A ...

We report the direct observation of one-dimensional (ID) excitonic molecules (biexcitons) in high quality disorder free semiconductor quantum wires. By means of spatially resolved near-field photoluminescence spectroscopy, we detected delocalized 1D excitons through the spatial extension of their homogeneous emission. 1D biexciton transitions are evidenced by their correlation to the 1D excitons as well as their power dependence. The photoluminescence intensity from biexcitons is shown to increase quadratic

Optical parametric oscillator including a semiconductor microcavity being configured to spatially localize polaritons of at least three quantized polariton energy levels to effect an optical parametric oscillation. ...

We present the results of a study of the dynamics of trions and excitons in a CdTe modulationdoped quantum well as a function of temperature in the low-density regime. Using three-pulse four-wave mixing technique, we show that, at low temperature, these quasi-particles are inhomo-geneously broadened and localized due to disorder effects. At higher temperatures, trions and excitons are mobile and their homogeneous broadening is largely increased as a result of acoustic phonon scattering. Consistently, time-r

Benoît Marie Joseph Deveaud

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Excitonic corrections and band gap renormalization in quantum wires

Ultrafast coherent control of excitons and exciton-polaritons in quantum nanostructure

Modeling the photoluminescence lifetime in realistic quantum wires

Negatively charged excitons in CdTe-based quantum wells: A time-resolved study

Impact of biexcitons on the relaxation mechanisms of polaritons in III-nitride based multiple quantum well microcavities

Charged exciton dynamics in GaAs quantum wells

Time-Resolved Optical Spectroscopies

Determination of the exciton formation in quantum wells from time-resolved interband luminescence

Temporally resolved second-order photon correlations of exciton-polariton Bose-Einstein condensate formation

Strong coherent gain from semiconductor microcavities in the regime of excitonic saturation

Probing excitonic nonlinearities in quantum wires

Theory of ultrafast Rayleigh scattering in semiconductor quantum wells

Dynamics of charged excitons in GaAs quantum wells under high magnetic field

Formation time of negatively charged excitons in CdTe-based quantum wells

Level repulsion of localised excitons observed in near-field photoluminescence spectra

Ultrafast phase-locked spectroscopy of excitons in quantum nanostructures

Exciton dynamics at a single dislocation in GaN probed by picosecond time-resolved cathodoluminescence

One-dimensional biexcitons in a single quantum wire

Near infrared twin photon source

Trions and excitons in CdTe quantum wells: Lifetimes, coherence, diffusion and localization