Los de Jordi
Shape dependent electronic structure and exciton dynamics in small In(Ga)As quantum dots
Jordi Gomis, Juan Martínez-Pastor, Benito Alén, Daniel Granados, Jorge M. García, and Philippe Roussignol
We present a study of the primary optical transitions and recombination dynamics in InGaAs
self-assembled quantum nanostructures with di®erent shape. Starting from the same quantum dot seeding layer, and depending on the overgrowth conditions, these new nanostructures can be tailored in shape and are characterized by heights lower than 2 nm and base lengths around 100 nm. The geometrical shape strongly influences the electronic and optical properties of these nanostructuctures. We measure for them ground state optical transitions in the range 1.25 - 1.35 eV and varying energy splitting between their excited states. The temperature dependence of the exciton recombination dynamics is reported focusing on the intermediate temperature regime (before thermal escape begins to be important). In this range, an important increase of the effective photoluminescence decay time is observed and attributed to the state filling and exciton thermalization between excited and ground states. A rate equation model is also developed reproducing quite well the observed exciton dynamics.
Complete ground state gain recovery after ultrashort double pulses in quantum dot based semiconductor optical amplifier
Sabine Dommers, Vasily V. Temnov, Ulrike Woggon, Jordi Gomis, Juan Martinez-Pastor, Matthias Laemmlin, Dieter Bimberg
Gain recovery dynamics are studied in electrically pumped quantum dot based semiconductor optical amplifiers (SOA) after amplifciation of double femtosecond laser pulses using ultrafast
pump-probe spectroscopy with heterodyne detection. We observe a distinct change in gain recovery in the ground state when a signi¯cant excited state population is achieved. A complete gain recovery is found when two 150 fs pulses with 5 ps time delay pass through the SOA in resonance to the ground state under high injection currents of 80 to 100 mA. The obtained results open the way for ultrafast (> 200 GHz) operation in p-doped QD-based SOAs at 1300 nm telecom wavelengths.
Este artículo marca un nuevo hito en nuestro grupo, tanto por las colaboraciones, como por el tema de trabajo, la óptica integrada, en el que esperamos contribuir positivamente con nuestros propios dispositivos.
Jordi Gomis, Juan Martínez-Pastor, Benito Alén, Daniel Granados, Jorge M. García, and Philippe Roussignol
We present a study of the primary optical transitions and recombination dynamics in InGaAs
self-assembled quantum nanostructures with di®erent shape. Starting from the same quantum dot seeding layer, and depending on the overgrowth conditions, these new nanostructures can be tailored in shape and are characterized by heights lower than 2 nm and base lengths around 100 nm. The geometrical shape strongly influences the electronic and optical properties of these nanostructuctures. We measure for them ground state optical transitions in the range 1.25 - 1.35 eV and varying energy splitting between their excited states. The temperature dependence of the exciton recombination dynamics is reported focusing on the intermediate temperature regime (before thermal escape begins to be important). In this range, an important increase of the effective photoluminescence decay time is observed and attributed to the state filling and exciton thermalization between excited and ground states. A rate equation model is also developed reproducing quite well the observed exciton dynamics.
Complete ground state gain recovery after ultrashort double pulses in quantum dot based semiconductor optical amplifier
Sabine Dommers, Vasily V. Temnov, Ulrike Woggon, Jordi Gomis, Juan Martinez-Pastor, Matthias Laemmlin, Dieter Bimberg
Gain recovery dynamics are studied in electrically pumped quantum dot based semiconductor optical amplifiers (SOA) after amplifciation of double femtosecond laser pulses using ultrafast
pump-probe spectroscopy with heterodyne detection. We observe a distinct change in gain recovery in the ground state when a signi¯cant excited state population is achieved. A complete gain recovery is found when two 150 fs pulses with 5 ps time delay pass through the SOA in resonance to the ground state under high injection currents of 80 to 100 mA. The obtained results open the way for ultrafast (> 200 GHz) operation in p-doped QD-based SOAs at 1300 nm telecom wavelengths.
Este artículo marca un nuevo hito en nuestro grupo, tanto por las colaboraciones, como por el tema de trabajo, la óptica integrada, en el que esperamos contribuir positivamente con nuestros propios dispositivos.
posted by JUAN at
3:28 p. m.
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