Regensburg 2010 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 48: Semiconductor Lasers
HL 48.8: Vortrag
Donnerstag, 25. März 2010, 11:30–11:45, H13
Time-resolved studies of a rolled-up semiconductor laser — •Christian Strelow1, Michael Sauer1, Sebastian Fehringer2, Tobias Korn2, Christian Schüller2, Andrea Stemmann1, Christian Heyn1, Detlef Heitmann1, and Tobias Kipp1,3 — 1Institut für Angewandte Physik und Zentrum für Mikrostrukturforschung, Universität Hamburg — 2Institut für Experimentelle und Angewandte Physik, Universität Regensburg — 3Institut für Physikalische Chemie, Universität Hamburg
We report on lasing in microtube bottle resonators that are fabricated by the self-rolling mechanism of thin strained semiconductor bilayers. The optical modes are confined by total internal reflection inside the thin walls of the AlGaAs/InAlGaAs microtubes with typically 42 nm wall thickness and about 2.4 µm radius. Constructive interference after a round trip leads to the formation of ring modes. In axial direction a special modulation of the wall thickness, similar to a ridge waveguide, confines the modes on a length of about 1.4 µm. A GaAs quantum well as optical gain material is excited nearly resonantly by sub-picosecond laser pulses. Time-resolved studies on this novel kind of semiconductor laser reveal particularly fast turn-on times and short pulse emission above the threshold, as well as single-mode lasing. We observe a strong redshift of the laser mode during the pulse emission which is compared to the time evolution of the charge-carrier density calculated by rate equations.