Posez n’importe quelle question sur les cours, conférences, exercices, recherches, actualités, etc. de l’EPFL ou essayez les exemples de questions ci-dessous.
AVERTISSEMENT : Le chatbot Graph n'est pas programmé pour fournir des réponses explicites ou catégoriques à vos questions. Il transforme plutôt vos questions en demandes API qui sont distribuées aux différents services informatiques officiellement administrés par l'EPFL. Son but est uniquement de collecter et de recommander des références pertinentes à des contenus que vous pouvez explorer pour vous aider à répondre à vos questions.
We present a comparative study of time-integrated four-wave-mixing and femtosecond emission under resonant excitation on excitons in weakly disordered GaAs quantum wells. At highest exciton densities when dephasing dominates the spectral width (homogeneous ...
P doping of gallium nitride by incorporation of magnesium in the layers was controlled recently. Only Popovici et al. [1] have published the results of a Raman study on p type GaN. In the present communication, we report on the interaction of the free hole ...
We report the first successful use, to our knowledge, of InAsP quantum wells for 1.55 mu m wavelength laser emission: 5 quantum well InAsP/InGaAsP horizontal cavity lasers showed 88% internal efficiency, 1.6 cm(-1) losses per well, and 33 A/cm(2) transpare ...
We report on the realization of InGaAs-lnGaAsP separate confinement heterostructure multiple quantum well lasers grown by chemical beam epitaxy. We discuss key growth parameters and characterization by secondary-ion mass spectroscopy, transmission electron ...
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 c ...
We develop a quantum mechanical model for the interaction of excitons in a microcavity embedded quantum well with a short resonant laser pulse. The model assumes full in-plane coherence. A Gaussian distribution of exciton slates is included in order to tak ...
Disclosed is a semiconductor laser that is constituted by at least one active layer sandwiched between two confinement layers with P and N type doping to constitute a PN junction. In at least one of the confinement layers and/or the active layer, holes are ...
The conduction band offset in ZnSe/GaAs n-p heterodiodes was determined from measurements of the low-temperature tunneling current of photoinjected carriers, We found widely different discontinuities for heterojunctions fabricated with different Zn/Se flux ...
The authors present low voltage barrier p-InP/p-GaAs junctions obtained by localised fusion which facilitates a better evacuation of absorbed gases and native oxides from the fused interface. Using this approach InGaAs/lnGaAsP/InP edge emitting lasers fuse ...
The Brillouin fibre laser has experimentally demonstrated its suitability for the measurement of laser linewidth in the 1 kHz to 500 kHz frequency range. A major advantage of this system is to be widely independent of the source wavelength by generating th ...