Publications de Elyahou Kapon | EPFL Graph Search

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The results of a group theoretical analysis of the excitonic fine structure are presented and compared with spectroscopic data on single quantum dots. The spectral features reveal the signatures of a symmetry higher than the crystal symmetry (C-3v). A cons ...

We present results on the polarization-resolved photoluminescence emitted from InGaAs/AlGaAs single quantum dots (QDs) grown in inverted tetrahedral pyramids. The emitted light was detected for two mutually perpendicular linear polarization directions in t ...

Emission wavelength setting of 1310nm-waveband VCSELs designed for coarse wavelength division multiplexing (CWDM) 4x10 Gbps fiber-optics transmission can be controlled thanks to the wafer fusion fabrication approach. This approach allows performing the cav ...

We have evaluated the structure of high-reflectivity InP/InGaAsP distributed Bragg reflectors grown by chemical-beam epitaxy at a growth rate of 3 mu m/h. Transmission electron microscopy combined with electron energy loss spectroscopy indicate lateral fluctuations in the GaInAsP alloy composition, clearly visible in the 490-510 degrees C growth temperature range, but less perceptible between 460 and 480 degrees C. In the higher temperature range, the modulation in composition shows a higher frequency along

Three means of optical confinement imposed on InAlGaAs/InP 1.3 mu m VCSEL arrays are investigated with self-consistent numerical model of laser operation. Laterally patterned tunnel junction (TJ), in-build guiding realized with air-gap patterning, and anti ...

The diffusivity of photogenerated electron-hole pairs in weakly disordered GaAs/AlGaAs V-groove quantum wires was measured using a photoluminescence (PL) time-of-flight technique. It is shown that the electron-hole pair diffusion is thermally activated above about 50 K. Exciton localization is observed in micro-PL (mu PL) spectra at low temperature. A reduction in the Stokes shift is found to accompany the increase in the diffusion coefficient. Nevertheless, localization-related features in the mu PL spectr

Pyramidal, site-controlled InGaAs/AlGaAs quantum dots (QDs) are studied by micro-photoluminescence (PL) spectroscopy in a magnetic field. The light-hole (LH) excitonic transitions exhibit diamagnetic shifts similar to those of their heavy-hole (HH) counterparts. From the evolution of the excitonic lines, effective g-factors of g = 1.7 and 0.4 for HH and LH neutral excitons are inferred. (c) 2007 Elsevier B.V. All rights reserved.

We study a specific type of lifetime broadening resulting in the well-known exponential "Urbach tail" density of states within the energy gap of an insulator. After establishing the frequency and temperature dependence of the Urbach edge in GaAs quantum we ...

We investigated experimentally 1D and 2D arrays of coupled L3 photonic crystal cavities. The optical modes of the coupled cavity arrays are fed by a site-controlled quantum wire light source. By performing photoluminescence measurements and relying on near ...

Mode control in wafer-fused 1.3 mu m wavelength coupled-VCSEL arrays is achieved by cavity structuring and investigated by spectrally resolved near- and far-field measurements. Improved mode discrimination is attained by combining index- and gain-patterning. (C)2010 Optical Society of America

We report the injection locking of specific spatial modes and polarization modes of 1.3 mu m wavelength vertical surface emitting lasers (VCSELs) in single-aperture devices and phase-coupled arrays. The optical injection is realized using a master laser (M ...

The engineering of the three-dimensional (3D) heterostructure potential in GaAs/AlGaAs pyramidal quantum dot-in-dots (DiDs) provides control over the valence band symmetry and hence on the polarization of the emitted photons. We propose a technique for dyn ...

We apply the modal coherence theory to evaluate the spatial mode structure of a 2 × 2 phase-coupled array of vertical cavity surface emitting lasers (VCSELs). The eigenmode structure is extracted for different pump currents by measuring the degree of spatial coherence of all VCSEL pairs in the array. The results reveal the impact of optical disorder and spatial hole burning on the modal discrimination. The approach is useful more generally for the evaluation of spatial mode content of other laser array.

We demonstrate an optically pumped semiconductor disk laser operating at 1580 nm with 4.6 W of output power, which represents the highest output power reported from this type of laser. 1 W of output power at 785 nm with nearly diffraction-limited beam has been achieved from this laser through intracavity frequency doubling, which offers an attractive alternative to Ti:sapphire lasers and laser diodes in a number of applications, e.g., in spectroscopy, atomic cooling and biophotonics. (C)2012 Optical Society

Recent progress in the fabrication and performance of 1.3-mu m 10-Gb/s, low power consumption wafer-fused VCSELs grown by MOVPE under nitrogen atmosphere are presented and discussed. By optimization of the growth conditions and implementation of a cavity a ...

Record fundamental mode output power of 8mW at 0 degrees C and 6.5mW at room temperature is achieved with wafer-fused VCSELs incorporating regrown tunnel junction and emitting at the 1550nm waveband. (C) 2009 Optical Society of America

A high-power InAs quantum dot (QD) vertical-external-cavity surface-emitting laser emitting at 1.5 mu m is reported. The active region employs 20 layers of high-density Stranski-Krastanow InAs quantum dots on an InP substrate. The QD density and emission w ...

We investigated theoretically the effects of the one-dimensional barriers on the electronic states in a quantum dot grown on a nonplanar substrate. These peculiar barriers drastically modify the confined carrier wave functions and their energies. Connecting the quantum wire to the pyramidal quantum dot leads to an enhancement in the ground to first excited state separation energy and a simultaneous large reduction of the energy size sensitivity. (C) 2004 American Institute of Physics.

Elyahou Kapon

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Symmetry Elevation and Symmetry Breaking: Keys to Describe and Explain Excitonic Complexes in Semiconductor Quantum Dots

Excited excitonic states observed in semiconductor quantum dots using polarization resolved optical spectroscopy

Wavelength control in fabrication of wafer fused VCSELs emitting in the 1310 nm waveband

Record-Low Inhomogeneous Broadening of Site-Controlled Quantum Dots for Nanophotonics

Evaluation of InP/InGaAsP distributed Bragg reflectors grown by chemical-beam epitaxy

Spatial-Mode Discrimination in Guided and Antiguided Arrays of Long-Wavelength VCSELs

Diffusion of electron-hole pairs in disordered quantum wires

Magneto-photoluminescence of heavy- and light-hole excitons in site-controlled pyramidal quantum dots

Measurements of the Electric Field of Zero-Point Optical Phonons in GaAs Quantum Wells Support the Urbach Rule for Zero-Temperature Lifetime Broadening

1D and 2D arrays of coupled photonic crystal cavities with a site-controlled quantum wire light source

Mode Control of 1.3 ∞m Wavelength Coupled VCSEL Arrays by Cavity Structuring

Optical injection locking of polarization modes and spatial modes in single-aperture VCSELs and VCSEL arrays emitting at 1.3 mu m

Dynamic switching of hole character and single photon polarization using the quantum confined Stark effect in quantum dot-in-dot structures

Eigenmode analysis of phased-coupled VCSEL arrays using spatial coherence measurements

1 W at 785 nm from a frequency-doubled wafer-fused semiconductor disk laser

Specific and efficient adsorption of phosphorothioated DNA on Au-based surfaces and electrodes

Fabrication and performance of 1.3-mu m 10-Gb/s CWDM wafer-fused VCSELs grown by MOVPE

8 mW Fundamental Mode Output of Wafer-Fused VCSELs Emitting in the 1550-nm Band

InAs/InP quantum dot VECSEL emitting at 1.5 mu m

Effects of the one-dimensional quantum barriers in pyramidal quantum dots