0000000000003114
AUTHOR
J. Gomis
Temperature dependent optical properties of stacked InGaAs/GaAs quantum rings
4 páginas, 3 figuras, 2 tablas.-- MADICA 2006 Conference, Fifth Maghreb-Europe Meeting on Materials and their Applicatons for Devices and Physical, Chemical and Biological Sensors
"Mad Men", "Los Soprano" y el "American way of life". Historia del capital en dos tiempos
Don Draper (Mad Men, Matthew Weiner, AMC: 2007-2015) participa del nacimiento y consolidación dela sociedad de consumo sin ser consciente de la gran ficción que intenta creerse. Tony Soprano (TheSopranos, David Chase, HBO: 1999-2007) se agarra desesperadamente a los últimos restos de un idealde superación y esfuerzo que no solo está agotado sino que nunca fue verdaderamente coherente. Estetexto realiza un análisis textual, sociológico y discursivo comparativo de ambas figuras en cuantorepresentativas de la evolución del discurso capitalista en la segunda mitad del siglo XX, es decir, laartificialidad del discurso hegemónico de búsqueda de la felicidad como uno de los grandes mitos delneolib…
Gain Dynamics after Ultrashort Pulse Trains in Quantum Dot based Semiconductor Optical Amplifiers
We study the gain dynamics in QD-based SOAs after excitation with fs-pulse trains of up to THz repetition rates. A complete ground-state gain recovery is found for 200 GHz repetition rates and injection currents around 90 mA.
Ultrafast Gain Recovery in Quantum Dot based Semiconductor Optical Amplifiers
Summary form only given. The limiting factor in ultrahigh bit rate amplification is the ultrafast population recovery in the resonant level, which is mainly limited by carrier capture and relaxation processes in the QD. We use pump-probe measurements resonant to the QDs confined states energies (ground and excited state) to investigate the response to a four fs-pulse train of 1 THz repetition rate. A deep insight about the capture process implied is then obtained, and direct capture from the wetting layer is identified as the dominant mechanism in the high current regime.
Size filtering effect in vertical stacks of In(Ga)As/GaAs self-assembled quantum rings
3 páginas, 3 figuras.
Exciton, biexciton and trion recombination dynamics in a single quantum dot under selective optical pumping
Continuous wave- and time-resolved micro-photoluminescence spectroscopy has been performed on single InAs self-assembled quantum dots grown on GaAs. The presence of residual impurities (donors and acceptors) in samples with low dot density opens the possibility to switch from trion to neutral exciton states inside quantum dots by selective optical pumping. We propose a microstate model to describe the recombination dynamics of all the excitonic especies (neutral exciton, positive/negative trion and biexciton) under the considered optical pumping conditions when increasing the excitation power. © 2007 Elsevier B.V. All rights reserved.
Effect of carrier transfer on the PL intensity in self-assembled In (Ga) As/GaAs quantum rings
We present results concerning the carrier transfer between In(Ga)As quantum rings in a stacked multilayer structure, which is characterised by a bimodal size distribution. This transfer of carriers explains the observed temperature behaviour of diode lasers based on that kind of stacked layer structures. The inter-ring carrier transfer can be possible by phonon assisted tunnelling from the ground state of the smallring family towards the big-ring family of the bimodal size distribution. This process is thermally activated in the range 40–80 K.