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Two‐color Femtosecond Spectroscopy of Blue‐Shifted InAs/AlGaAs Quantum Dots
Author(s) -
Betz M.,
Trumm S.,
Leitenstorfer A.,
Beham E.,
Krenner H.,
Bichler M.,
Zrenner A.,
Abstreiter G.
Publication year - 2002
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/1521-3951(200210)233:3<401::aid-pssb401>3.0.co;2-e
Subject(s) - quantum dot , femtosecond , excited state , wetting layer , picosecond , spectroscopy , relaxation (psychology) , ground state , materials science , quantum dot laser , ultrashort pulse , femtochemistry , molecular physics , optoelectronics , atomic physics , physics , optics , laser , semiconductor , semiconductor laser theory , psychology , social psychology , quantum mechanics
Ultrafast relaxation phenomena in self‐organized InAs/AlGaAs quantum dots with ground state transition energies of 1.42 eV are analyzed with different methods of femtosecond spectroscopy. A time‐correlated luminescence experiment of an ensemble of InAs islands reveals a picosecond relaxation mechanism of carriers within the quantum dots. Moreover, modifications of the quantum dot properties due to excitation of the surrounding wetting layer is found. Employing a shadow‐mask technique, a structure containing only a few zero‐dimensional objects is studied. Selectively creating electron–hole pairs in excited states of approximately ten quantum dots, we observe characteristic line shifts of their ground state absorption in a two‐color femtosecond transmission experiment. This finding demonstrates the feasibility of ultrafast studies of single self‐assembled quantum dots.