Publications de Elyahou Kapon | EPFL Graph Search

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We report on efficient, narrow linewidth exciton recombination in GaAs/AlGaAs V-groove quantum wire light-emitting diodes at room temperature. The high efficiency is due to a selective carrier injection mechanism resulting in an estimated internal quantum efficiency of similar to 20% with an electroluminescence (EL) linewidth as narrow as 15 meV. The thermal broadening contribution to the linewidth is 6 meV due to exciton scattering with optical phonons. An analysis of the EL peak shift in a magnetic field

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 present a detailed study of biexciton complexes formed in single, site-controlled pyramidal GaInAs/GaAs quantum dots (QDs). By using power dependent measurements and photon correlation spectroscopy, we identify the excitonic transitions of a large numbe ...

We have studied the effect of disorder on the radiative properties of semiconductor quantum wires by time-resolved photoluminescence spectroscopy. The dependence of the radiative lifetimes is measured over a temperature range extending from 8 to 150 K. At low temperatures we find that the measured dependence does not conform to the theoretical prediction for recombination of free excitons in a quasi-one-dimensional system due to the major influence of disorder. An extension of the theory is developed in ord

By using chemical beam epitaxy at growth temperatures as low as 460-480 degrees C, we have overcome strain relaxation problems that prevented so far the successful use of InAsP quantum wells in 1.55 mu m lasers. Five quantum well InAsP/InGaAsP horizontal cavity lasers showed 88% internal efficiency, 1.6 cm(-1) losses per well, and 33 A/cm(2) transparency current density per well, which equal or even surpass the best published characteristics for 1.55 mu m wavelength lasers based on any material system. More

Arrays of site-controlled, pyramidal InGaAs/GaAs quantum dots (QDs) grown by organo-metallic chemical vapour deposition with densities comparable to those of self-assembled QDs (5 x 109 cm(-2)) are demonstrated. The QDs exhibit high quality photoluminescen ...

We demonstrate selective optical coupling of multiple, site controlled semiconductor quantum dots (QDs) to photonic crystal waveguide structures. The impact of the exact position and emission spectrum of the QDs on the coupling efficiency is elucidated. Th ...

We report on transverse mode discrimination in long-wavelength wafer-fused vertical-cavity surface-emitting lasers (VCSELs) incorporating ring-shaped air gap patterns at the fused interface between the active region and the top distributed Bragg reflector (DBR). These 60-nm deep patterns were implemented with the aim of favoring the fundamental mode while preserving high output power. The VCSELs under consideration emit in the 1310-nm band and incorporate an AlGaInAs-based quantum well active region, a regr

Interactions of site-controlled quantum dots with a high-order cavity mode of an L7-type photonic crystal cavity are resolved spatially and spectrally. We observed a spatial avoided crossing in polarization-resolved optical emission of quantum dots. ...

Photoluminescence intensity and emission wavelength of InAsP/InGaAsP and InGaAs/InGaAsP multi-quantum well (MQW) laser structures grown by chemical beam epitaxy (CBE) at 460 degrees C and V/III ratio of 2 are considerably affected by annealing at temperatures 600-650 degrees C which prevents lasing of these structures fused on GaAs substrates. It is shown that the degradation of luminescence characteristics can be decreased by increasing the growth temperature to 480 degrees C and V/III ratio to 4. InAsP/In

We demonstrate efficient, regulated single-photon operation from site-controlled InGaAs quantum dots (QDs) grown on a prepatterned substrate. Under nonresonant optical excitation, carriers trapped at structural or compositional defects of the adjacent nano ...

We report the fabrication and the performance of phase-locked VCSEL arrays emitting near 1310 nm wavelength. The arrays were fabricated using double wafer fusion by patterning a tunnel junction layer, which serves to define the individual single mode array elements. Phase-locking in both one-dimensional and two-dimensional array configurations was confirmed by means of far field and spectral measurements as well as theoretical modeling. CW output powers of more than 12 mW were achieved. (C) 2009 Optical Soc

The fabrication and characterization of site-controlled InGaAs/GaAs quantum dots (QDs) made by MOVPE using triethylgallium (TEGa) on patterned {111}B GaAs substrates are reported. Results are compared to more traditional pyramidal QD structures grown emplo ...

Direct modulation at > 25 Gbps is achieved with 1310 nm wavelength wafer fused VCSELs by adjusting the strain in the quantum well active region and the cavity photon lifetime. 25 + Gbps large signal modulation with 10(-12) BER at 1310 nm across 10 km of st ...

Spectral dependence of Lamb coupling constant C is experimentally investigated in an InGaAlAs Quantum Wells active medium. An Optically-Pumped Vertical-External-Cavity Surface-Emitting Laser is designed to sustain the oscillation of two orthogonally polari ...

We have studied the effect of valence band mixing on the optical properties of semiconductor quantum wires by analyzing the luminescence polarization. Large polarization anisotropy is observed and directly compared to the effects predicted by a k . p model calculation of the valence band structure.

We report 1.3-mu m mode-locked optically pumped semiconductor disk laser (SDL) made by wafer fusion. The gain medium and the saturable absorber, both based on an InP material system, were integrated with AlGaAs-GaAs distributed Bragg reflectors by localize ...

We demonstrate the cavity quantum electrodynamics towards strong- coupling regime mediated by cavity loss and exciton pure dephasing in singular site-controlled quantum dotnanocavity system, studied by micro-photoluminescence (mu-PL) and time- resolved PL ...

We present the static and optical injection response of wafer-fused long-wavelength VCSELs with and without intracavity patterning. It is found that the extra optical cavity patterning increases the gain anisotropy between orthogonal polarization modes, in ...

10-Gb/s modulation speed and transmission over 10-km SM fiber with BER < 10(-11) up to 100 degrees C temperature are achieved with optimized wafer-fused GaAs/AlGaAs-InP/InAlGaAs VCSELs incorporating re-grown tunnel junction. These VCSELs operate in the 1310-nm waveband and emit more than 1-mW single mode power in the full temperature range. (C) 2009 Optical Society of America

Elyahou Kapon

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Efficient, narrow linewidth excitonic emission at room temperature from GaAs/AlGaAs V-groove quantum wire light-emitting diodes

Excitonic corrections and band gap renormalization in quantum wires

Bound and anti-bound biexciton in site-controlled pyramidal GaInAs/GaAs quantum dots

Effect of disorder on the temperature dependence of radiative lifetimes in V-groove quantum wires

Low Threshold 1.55 µm Wavelength InAsP/InGaAsP Strained Multi-Quantum Well Laser Diode Grown by Chemical Beam Epitaxy

Dense arrays of pyramidal quantum dots with narrow linewidth photoluminescence spectra

Site-controlled quantum dots coupled to photonic crystal waveguides

Improved single-mode emission characteristics of long-wavelength wafer-fused vertical-cavity surface-emitting lasers by intra-cavity patterning

Spatial Avoided Crossing in Optical Emission of Site-Controlled Pyramidal Quantum Dots in Photonic Crystal Cavities

Thermal Stability of InP-Based Structures for Wafer Fused Laser Diodes

Optimization of the efficiency of single photon sources based on quantum dots under optical excitation

1.3µm-wavelength phase-locked VCSEL arrays incorporating patterned tunnel junction

Site-controlled InGaAs/GaAs pyramidal quantum dots grown by MOVPE on patterned substrates using triethylgallium

25 Gbps direct modulation and 10 km data transmission with 1310 nm waveband wafer fused VCSELs

Direct measurement of the spectral dependence of Lamb coupling constant in a dual frequency quantum well-based VECSEL

Polarization anisotropy and valence band mixing in semiconductor quantum wires

1.3-μm Mode-Locked Disk Laser With Wafer Fused Gain and SESAM Structures

Towards strong-coupling regime in singular site-controlled InGaAs quantum dots-nanocavities

Optical Injection and Lasing Dynamics in Long-Wavelength VCSELs With Intracavity Patterning

10Gb/s and 10km error-free transmission up to 100ºC with 1.3µm wafer-fused VCSELs