Regensburg 2010 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 48: Semiconductor Lasers
HL 48.3: Vortrag
Donnerstag, 25. März 2010, 10:00–10:15, H13
Effects of 1st order Coulomb Interaction on the Turn-on Dynamics of Quantum Dot Lasers — •Benjamin Lingnau1, Kathy Lüdge1, Eckehard Schöll1, and Weng Chow2 — 1Institut f. Theo. Physik, Sekr. EW 7-1, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin, Germany — 2Sandia National Laboratories, Albuquerque, New Mexico 87185-1086, USA
We investigate the influence of many-body and nonequilibrium effects on the turn-on dynamics of a quantum dot laser. The interplay of bandgap renormalization, population hole-burning and inhomogeneous broadening is crucial for understanding the dynamics of the turn-on process and gives rise to modifications in relaxation oscillation behaviour. The theory used in the simulations is based on a semiclassical approach, where the laser field and active medium are described by the Maxwell-semiconductor-Bloch equations. Many-body Coulomb effects are described in the screened Hartree-Fock approximation. Carrier-carrier and carrier-phonon collisions are treated within the effective relaxation rate approximation. Inhomogeneous broadenening of the quantum-dot distribution is taken into account. Many-body effects were found to have a large effect on the turn-on dynamics of the laser device and especially on the relaxation oscillations after turn-on. We observe a noticeable increase in oscillation frequency and a stronger damping due to the bandgap renormalization. Furthermore, when changing the width of the inhomogeneously broadened quantum dot distribution, increasing frequencies and more pronounced oscillations for smaller broadening widths are observed.