A5077601854- Photonic and Optical Devices
- GaN-based semiconductor devices and materials
- Semiconductor Quantum Structures and Devices
- Semiconductor Lasers and Optical Devices
- Photonic Crystals and Applications
- ZnO doping and properties
- Ga2O3 and related materials
- Nanowire Synthesis and Applications
- Strong Light-Matter Interactions
- Advanced Fiber Laser Technologies
- Plasmonic and Surface Plasmon Research
- Mechanical and Optical Resonators
- Quantum Information and Cryptography
- Metal and Thin Film Mechanics
- Quantum and electron transport phenomena
- Semiconductor materials and devices
- Advanced Optical Sensing Technologies
- Thermal Radiation and Cooling Technologies
- Advanced Fiber Optic Sensors
- Neural Networks and Reservoir Computing
- Metamaterials and Metasurfaces Applications
- Quantum Dots Synthesis And Properties
- Advanced Semiconductor Detectors and Materials
- 2D Materials and Applications
- Near-Field Optical Microscopy
Université Côte d'Azur
2019-2025
Observatoire de la Côte d’Azur
2020-2025
École Polytechnique Fédérale de Lausanne
2004-2024
Centre National de la Recherche Scientifique
2012-2024
Centre de Recherche sur l'Hétéro-Epitaxie et ses Applications
2012-2024
Columbia Region Healthcare Engineers Association
2020-2024
Hitachi (United Kingdom)
2008
We have optimized the molecular-beam epitaxy growth conditions of self-organized InAs∕GaAs quantum dots (QDs) to achieve a low density emitting at 1300 nm temperature. used an ultralow InAs rate, lower than 0.002ML∕s, reduce 2dots∕μm2 and InGaAs capping layer longer emission wavelength. Microphotoluminescence spectroscopy low-temperature reveals lines characteristic exciton-biexciton behavior. also study temperature dependence photoluminescence, showing clear single QD up 90 K. With these...
We present time integrated and time-resolved photoluminescence (PL) measurements on a single InAs∕GaAs quantum dot (QD), embedded in planar microcavity, emitting the 1300nm telecom band. The results of both clearly identify exciton biexciton transitions from QD. By optimizing extraction efficiency QD PL into mode fibers carefully tuning two InGaAs avalanche photodiodes, we were able to measure second order correlation function with integration times comparable those made silicon based...
Post-growth in situ partial SiNx masking of GaN-based epitaxial layers grown a molecular beam epitaxy reactor is used to get GaN selective area sublimation (SAS) by high temperature annealing. Using this top-down approach, nanowires (NWs) with nanometer scale diameter are obtained from and InxGa1-xN/GaN quantum well structures. After regrowth on NWs resulting SAS, InxGa1-xN disks (QDisks) sizes the three dimensions formed. Low microphotoluminescence experiments demonstrate QDisk multilines...
The development of flexible optoelectronic devices has led to the appearance new applications, ranging from wearable displays medical implants. Hence, strategies have been developed make every component devices, including light-emitting part. One such approach relies on use micro- or nano-light emitting diodes (LEDs) for their reduced footprint, allowing them be easily separated substrate and embedded in a matrix. In this review, authors provide comparison between different geometries...
The authors report fiber-coupled superconducting single-photon detectors with specifications that exceed those of avalanche photodiodes, operating at telecommunication wavelength, in sensitivity, temporal resolution, and repetition frequency. improved performance is demonstrated by measuring the intensity correlation function g(2)(τ) states 1300nm produced single semiconductor quantum dots.
We demonstrate that the presence of charges around a semiconductor quantum dot (QD) strongly affects its optical properties and produces nonresonant coupling to modes microcavity. show that, besides (multi)exciton lines, QD generates spectrally broad emission which efficiently couples cavity modes. Its temporal dynamics shows it is related Coulomb interaction between (multi)excitons carriers in adjacent wetting layer. This mechanism suppressed by application an electric field, making closer...
Abstract Nano-engineering III-nitride semiconductors offers a route to further control the optoelectronic properties, enabling novel functionalities and applications. Although variety of lithography techniques are currently employed nano-engineer these materials, scalability cost fabrication process can be an obstacle for large-scale manufacturing. In this paper, we report on use fast, robust flexible emerging patterning technique called Displacement Talbot (DTL), successfully materials....
The advance in designing arrays of ultrathin two-dimensional optical nano-resonators, known as metasurfaces, is currently enabling a large variety novel flat components. remarkable control over the electromagnetic fields offered by this technology can be further extended to active regime order manipulate light characteristics real-time. In contribution, we couple excitonic resonance atomic thin MoS2 monolayers with gap-surface-plasmon (GSP) and demonstrate selective enhancement...
The polarity of GaN micro- and nanowires grown epitaxially by metal organic vapor phase epitaxy on sapphire substrates molecular-beam epitaxy, using ammonia as a nitrogen source, silicon has been investigated. On Al2O3(0001), whatever the growth technique employed, wires show mixture Ga N polarities. Si(111), ammonia-molecular beam are almost entirely Ga-polar (around 90%) do not inversion domains. These results can be understood in terms conditions employed during nucleation stage.
GaN microwires grown by metalorganic vapour phase epitaxy and with radii typically on the order of 1-5 micrometers exhibit a number resonances in their photoluminescence spectra. These include whispering gallery modes transverse Fabry-Perot modes. A detailed spectroscopic study polarization-resolved microphotoluminescence, combination electron microscopy images, has enabled to differentiate both kinds determined main spectral properties. Finally, dispersion ordinary extraordinary refractive...
Abstract The early growth stages of GaN nanowires on GaN-on-sapphire templates with a patterned dielectric mask have been characterized by using transmission electron microscopy. aperture (200–800 nm) determines the presence or absence threading dislocations arising from underlying template, which results in dislocation-free for small apertures and dislocation bending larger apertures, owing to three-dimensional (3D) growth. Ga polarity template is conserved all irrespective size, even...
A novel light-emitting-diode structure is demonstrated, which relies on nanoscale current injection through an oxide aperture to achieve selective excitation of single InAs/GaAs quantum dots. Low-temperature electroluminescence spectra evidence discrete narrow lines around 1300 nm (line width ≈ 75 μeV) at ultralow currents, are assigned the emission from excitons and multiexcitons. This approach, enables fabrication efficient active devices nm, can provide single-photon-emitting diodes for...
We report direct evidence of enhanced spontaneous emission in a photonic crystal (PhC) light-emitting diode. The device consists p-i-n heterojunction embedded suspended membrane, comprising layer self-assembled quantum dots. Current is injected laterally from the periphery to center PhC. A well-isolated peak at 1300nm PhC cavity mode observed, and enhancement rate clearly evidenced by time-resolved electroluminescence measurements, showing that our diode switches off time shorter than bulk...
Self-assembled InAs∕GaAs quantum dots have been grown at very low InAs growth rate in order to form sparse and large (QDs) emitting the near infrared (1300–1400nm), for application as single-photon sources. The structural optical properties of these QDs a function were systematically investigated. lowest (∼10−3ML∕s) present dot density (∼2×108dots∕cm2), high In content, good size homogeneity. Photoluminescence time-resolved photoluminescence measurements performed different powers...
We describe the design and characterization of a fiber-coupled double-channel single-photon detection system based on superconducting detectors (SSPD), its application for quantum optics experiments semiconductor nanostructures. When operated at 2-K temperature, shows 10% efficiency 1.3-¿m wavelength with dark count rate below 10 counts per second timing resolution <100 ps. The short recovery time absence afterpulsing leads to counting frequencies as high 40 MHz. Moreover, low allows...
Site‐controlled growth of GaN nanowires (NWs) on GaN‐on‐sapphire templates with a patterned SiN mask has been carried out by metalorganic vapor phase epitaxy using continuous‐flow mode. A low V/III ratio compared to that used for layer growth, combined precursor flow rates both Ga and N precursors, promote the nanowire Ga‐polar substrates. The lateral rate, is, perpendicular c ‐axis, could be further controlled appropriate temperatures H 2 /N ratios. Besides, influence pattern geometry...
We present a comparative study of carrier diffusion in semiconductor heterostructures with different dimensionality [$\mathrm{InGaAs}$ quantum wells (QWs), $\mathrm{InAs}$ dots (QDs), and disordered $\mathrm{InGaNAs}$ QWs (DQWs)]. In order to evaluate the length active region device structures, we introduce method based on measurement current-voltage light-current characteristics light-emitting diodes where current is injected an area...
The authors demonstrate coupling at 1.3μm between single InAs quantum dots (QDs) and a mode of two dimensional photonic crystal (PhC) defect cavity with quality factor 15 000. By spectrally tuning the mode, they induce excitonic lines. They perform time integrated time-resolved photoluminescence measure an eightfold increase in spontaneous emission rate inducing efficiency 96%. These measurements indicate potential QDs PhC cavities as efficient single-photon emitters for fiber-based...
We report a “plug and play” single photon source, fully integrated with an optical fiber, emitting at 1.3μm. Micropillars were patterned on layer InAs quantum dot wafer to guarantee pillar per fiber core. The exciton peak filtered tunable filter was fed Hanbury Brown Twiss interferometer, the second order correlation function zero delay less than 0.5, indicating emission. measured decay dynamics under double-pulse excitation show that device can be operated speeds greater 0.5GHz.
Large bandgap semiconductor microwires constitute a very advantageous alternative to planar microcavities in the context of room temperature strong coupling regime between exciton and light. In this work we demonstrate that GaN microwire, is achieved up with large Rabi splitting 125 meV never before Nitride-based photonic nanostructure. The demonstration relies on method which doesn't require any knowledge \'a priori eigenmodes energy i.e. details microwire cross-section shape. Moreover,...
Abstract Quantum well nanolasers usually show single‐mode lasing, as gain saturation suppresses emissions in other modes. In contrast, for whispering gallery mode microdisk lasers with GaN quantum wells active material, above threshold multimode laser emission is observed. This intriguing feature manifested the fact that several modes simultaneously characteristic kink input–output curve at onset of lasing. A theory used to support experimental finding and analyze this behavior presence...
Abstract The mass production of µLEDs requires an upscaling approach on 200 mm wafers, which implies the deployment a technology that achieves zero defectivity without liftoff. In this report, Nanoimprint lithography (NIL) processing is successfully optimized for nanostructuring GaN‐based Silicon‐On‐Insulator (SOI) substrates. etching SiO 2 /GaN/AlN/Si/SiO layers using different plasmas conducted and multi‐layer nanopillars 100–200 in diameter are fabricated. This generates zero‐defect...