Düsseldorf 2007 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 33: Poster Präzisionsmessungen
Q 33.3: Poster
Tuesday, March 20, 2007, 16:30–18:30, Poster C
THz-operation of Quantum Dot based Semiconductor Optical Amplifiers — •Sabine Dommers1, Vasily Temnov1, Ulrike Woggon1, Jordi Gomis2, Juan Martinez-Pastòr2, Matthias Lämmlin3, and Dieter Bimberg3 — 1FB Physik, Universität Dortmund, 44221 Dortmund — 2nstitut de Ciència dels Materials, Universitat de València, 46071 València, Spanien — 3Institut für Festkörperphysik, Technische Universität Berlin, 10623 Berlin
The amplification of ultrashort pulse trains in an electrically pumped quantum dot (QD) based semiconductor optical amplifier is investigated by ultrafast pump-probe spectroscopy. The amplifier consists of an electrically contacted deeply etched ridge waveguide with a width of 2 µm and a length of 1 mm. The active medium is formed by 15 layers of MBE-grown InGaAs QD-in-a-well nanostructures. Ultrashort pulse trains consisting of up to four identical 150-fs-long Ti:Saphire laser pulses with a controllable delay in a picosecond time range are obtained using two unbalanced Michelson interferometers. The gain dynamics after amplification of ultrashort pulse trains are monitored as a function of pump-probe delay time. We report on a complete gain recovery in the amplification of double pulses separated by 5 picoseconds (equivalent of 200 GHz repetition rate) [1] and discuss the limits of THz amplification (pulse separation 1 ps) on the basis of the experiments with four pulse trains.
[1] Dommers, et al., Appl. Phys. Lett. (in print)