A5055876292- Photonic and Optical Devices
- Semiconductor Lasers and Optical Devices
- Semiconductor Quantum Structures and Devices
- solar cell performance optimization
- Nanowire Synthesis and Applications
- Photonic Crystals and Applications
- Molecular Junctions and Nanostructures
- Semiconductor materials and interfaces
- Semiconductor materials and devices
- Chalcogenide Semiconductor Thin Films
- GaN-based semiconductor devices and materials
- Thin-Film Transistor Technologies
- Optical Coatings and Gratings
- Optical Network Technologies
- Silicon and Solar Cell Technologies
- Spectroscopy and Laser Applications
- Advanced optical system design
- Advanced Semiconductor Detectors and Materials
- Silicon Nanostructures and Photoluminescence
- Advanced Fiber Laser Technologies
- Advancements in Semiconductor Devices and Circuit Design
- Quantum Dots Synthesis And Properties
- Analytical Chemistry and Sensors
- Nanofabrication and Lithography Techniques
- Mechanical and Optical Resonators
Fonctions Optiques pour les Technologies de l’information
2015-2024
Institut National des Sciences Appliquées de Rennes
2012-2024
Université de Rennes
2019-2024
Centre National de la Recherche Scientifique
2013-2024
McMaster University
2021
Université Rennes 2
2019-2021
Foton Motors (China)
2006-2019
Université Européenne de Bretagne
2008-2015
Bellingham Technical College
2015
Laboratoire d'Analyse et d'Architecture des Systèmes
2007-2010
We compare the potentiality of bulk InGaPN and GaAsPN materials quasi-lattice-matched to silicon (Si), for multi-junction solar cells application. Bandgaps both alloys are first studied by a tight-binding model modified nitrogen incorporation in diluted regimes. The critical thicknesses those then calculated various compositions. For same lattice-mismatch amount, bandgap is found be closer targeted gap value 1.7 eV high efficiency tandem cell. GaPN epilayers grown molecular beam epitaxy on...
Hybrid materials taking advantage of the different physical properties are highly attractive for numerous applications in today's science and technology. Here, it is demonstrated that epitaxial bi-domain III-V/Si hybrid structures, composed bulk photo-active semiconductors with 2D topological semi-metallic vertical inclusions, endowed ambipolar properties. By combining structural, transport, photoelectrochemical characterizations first-principle calculations, shown able within same layer to...
We present a quantitative study on the fabrication of microlenses using low-cost polymer dispending technique. Our method is based use silicon micro-cantilever robotized spotter system. first give detailed description In second part, fabricated are fully characterized by means SEM (Scanning Electron Microscope), AFM (Atomic Force Microscopy) non contact optical profilometry and Mach-Zehnder interferometry. Diameters in range [25-130mum] obtained with an average surface roughness 2.02nm....
A tunable vertical-cavity surface-emitting laser is fabricated where tunability achieved with an intracavity layer of nematic liquid crystal and gain provided by a semiconductor quantum well structure. The anisotropic enables continuously single-mode emission along the extraordinary axis layer. Polarization control when thickness such that ordinary modes are out spectral region. Laser in 1.5μm telecom wavelength range demonstrated under optical pumping tuning more than 30 nm for applied...
Abstract GaAsPN semiconductors are promising material for the development of high-efficiency tandem solar cells on silicon substrates. diluted-nitride alloy is studied as top-junction due to its perfect lattice matching with Si substrate and ideal bandgap energy allowing a current bottom cell. The GaP/Si interface also in order obtain defect-free pseudo-substrates suitable subsequent top junctions growth. Result shows that double-step growth procedure suppresses most microtwins bi-stepped...
We demonstrate the output beam collimation of GaAs-based vertical-cavity surface-emitting lasers by means self-aligned polymer microlenses deposited on SU-8 pedestals using a cantilever-based spotter. show that this fabrication technique ensures reproducible lens shape because contact angle and volume are constant for given surface. Device properties presented compared to optical propagation modeling results. final divergence is only controlled pedestal design parameters can be reduced with...
A simple technology is demonstrated for the wafer-scale fabrication of liquid-crystal (LC) microcells that can be integrated in active optoelectronic devices. Fabrication 1.55-μm tunable Fabry-Perot optical micro-filter arrays achieved owing to insertion a single nanoimprinted polymer grating dedicated LC alignment and soft thermal transfer dry thick resist film between two highly reflective mirrors. The filter exhibits spectral tuning range 102 nm with only 18 V applied, as well negligible...
A membrane external-cavity surface-emitting laser (MECSEL) with an InAs/InP quantum dot (QD) based gain region is demonstrated. The pumping scheme employs a 90° off-axis parabolic mirror to focus the diode pump beam nearly circular spot. With this arrangement, QD MECSEL SiC heat spreaders produced 320 mW output power at room temperature direct emission in near-infrared 1.5 μm. We report record value of 86 nm for tuning range wavelength region, owing broad bandwidth and wide tunability MECSELs.
We have used magnetophotoluminescence to study the impact of different capping layer material combinations (InP, GaInAsP quaternary alloy, or both InP and alloy) on lateral confinement in InAs∕InP quantum dots (QDs) grown (311)B orientated substrates. Exciton effective masses, Bohr radii, binding energies are measured for these samples. Conclusions regarding strength samples supported by photoluminescence at high excitation power. Contrary theoretical predictions, InAs QDs alloy found better...
We have performed time-resolved resonant pump-probe experiment to study the dynamic response of InAs∕InP quantum dot transitions. A 72-stacked layer sample is grown on (311)B substrate. Photoluminescence at high excitation power reveals ground and excited Carrier radiative lifetimes differential transmission are determined under strong powers. The variation measured carrier with increasing powers attributed exciton biexciton difference. implications such a difference discussed, finally be...
We report on the design and fabrication of polymer microlenses fabricated patterned SU-8 layers in view integrating VCSEL arrays for laser beam shaping. For a standard top-emitting VCSEL, lens has to be thick intermediate layer (pedestal) whose optimal thickness can modelled as function initial aimed optical properties beam. In this work, pedestals are with SU-8, which is negative-tone photoresist transparent at lasing wavelength. Lens deposition realized using robotized silicon...
Hydrogen produced using artificial photosynthesis, <italic>i.e.</italic> water splitting, is a promising energy alternative to fossil fuels.
An InP-based Vertical-Cavity Surface-Emitting Laser (VCSEL) with a liquid crystal (LC) microcell monolithically integrated on its surface for spectral tuning is investigated. Unlike tunable VCSELs integrating movable membrane, here the physical length of cavity remains unchanged and only voltage applied LC ensures refractive index modification particular polarization emitted by VCSEL. This VCSEL operates in CW at room temperature exhibits more than 23 nm wavelength around 1.55 μm maximum 20...
We present the first demonstration of a vertical cavity surface emitting laser (VCSEL) based on InAs quantum dots (QDs) InP. A very high density 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sup> cm xmlns:xlink="http://www.w3.org/1999/xlink">-2</sup> per QD layer, and thin spacing layer 15 nm are used to enhance modal gain within VCSEL cavity. Continuous wave (CW) operation is demonstrated at room temperature optically pumped devices...
We report the observation of enhanced charge-carrier redistribution in laterally organized and coupled $\mathrm{In}\mathrm{As}∕\mathrm{In}\mathrm{P}$ quantum dots (QDs). show that a periodic organization appears QD plane for high in-plane density (QDD). This enhances lateral coupling between dots, which is evidenced by photoluminescence magnetophotoluminescence experiments. Electronic inter-QD results an improved distribution at low temperature, as shown electroluminescence on QDD lasers....
A high-power InAs quantum dot (QD) vertical-external-cavity surface-emitting laser emitting at 1.5 μm is reported. The active region employs 20 layers of high-density Stranski–Krastanow dots on an InP substrate. QD density and emission wavelength were independently adjusted by employing a double-cap growth sequence. Optimization the spacer layer thickness strain compensation rendered possible nucleation relatively high number per antinode electromagnetic standing wave, which in turn enabled...
Highly polar materials are usually preferred over weakly ones to study strong electron-phonon interactions and its fascinating properties. Here, we report on the achievement of simultaneous confinement charge carriers phonons at vicinity a 2D vertical homovalent singularity (antiphase boundary, APB) in an (In,Ga)P/SiGe/Si sample. The impact interaction photoluminescence processes is then clarified by combining transmission electron microscopy, X-ray diffraction, ab initio calculations, Raman...
Subpicosecond optical transmission experiments are used to compare saturable absorber (SA) based on bundled single-walled carbon nanotubes (SWNT) and iron-doped InGaAs/InP epitaxial multiple quantum wells (MQW) at 1.55 μm telecom wavelength. The SA key parameters (contrast ratio, saturation fluence, recovery time) relevant for high speed all signal regeneration (AOSR) extracted from the normalized differential (NDT). Although both exhibit good contrast ratios, SWNT show a full as well much...
The authors report the demonstration of a polarization-controlled vertical-cavity surface-emitting laser (VCSEL), emitting at telecommunication wavelength. VCSELs are based on an active medium constituted well elongated InAs quantum dashes (QDHs) nanostructures grown conventional (001) oriented InP substrate. QDHs present important optical polarization anisotropies according to [11¯0] crystallographic orientation. Inserted into VCSEL microcavity, QDH show continuous wave operation 1.6 μm,...
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The first oxide-confined GaSb-based vertical-cavity surface emitting laser operating in the mid-infrared is demonstrated. Laser operation at −20°C continuous wave achieved with a device around 2.3 µm. influence of lateral confinement on performances presented and discussed.
Abstract We demonstrate an interband cascade resonant cavity light emitting diode (IC-RCLED) operating near 3.3 µ m at room temperature. The device is composed of a Sb-based type-II interband-cascade active zone enclosed between two distributed Bragg mirrors (DBR). bottom high reflective DBR GaSb/AlAsSb quarter-wave layers. A metamorphic III-As region grown after the to benefit from AlOx technology for efficient electro-optical confinement. structure finished with top ZnS/Ge dielectric DBR....