Berlin 2012 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 86: Semiconductor Lasers
HL 86.1: Vortrag
Donnerstag, 29. März 2012, 15:00–15:15, EW 015
Many-Body Effects in Optically Injected Quantum-Dot Lasers — •Benjamin Lingnau1, Kathy Lüdge1, Weng W. Chow2, and Eckehard Schöll1 — 1Institut f. Theo. Physik, Sekr. EW 7-1, Technische Universität Berlin, Hardenbergstr. 36, 10623Berlin, Germany — 2Sandia National Laboratories, Albuquerque, New Mexico 87185-1086, USA
We investigate the reaction of a quantum-dot (QD) laser to external optical injection. The QD laser device is described using a semi-classical approach, based on the semiconductor-Bloch and Maxwell’s equations, describing the material-light interaction in a quantum-mechanical framework and the electric field dynamics classically. The optical QD transition is modeled using a finite spectral width, accounting for inhomogeneities of the QDs. Carrier-carrier and carrier-phonon scattering of charge carriers in bulk, quantum well (QW) and QD states are considered within the relaxation rate approximation, where the QD-QW scattering rate exhibits a strongly nonlinear dependence on the QW charge carrier density. Furthermore, many-body Coulomb interactions, leading to renormalizations of the single-particle energies, are taken into account within the screened Hartree-Fock approximation.
When subjecting the laser to external optical injection, the dynamical shift of the band-gap energy due to the Coulomb interactions gives rise to modifications in the locking behavior of the laser, which can not be explained with simpler free-carrier models.