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Towards a mid‐infrared polaron laser using InAs/GaAs self‐assembled quantum dots
Author(s) -
Sauvage S.,
Boucaud P.,
Bras F.,
Fishman G.,
Ortéga J.M.,
Gérard J.M.,
Patriarche G.,
Lemaître A.
Publication year - 2006
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/pssb.200671517
Subject(s) - dephasing , polaron , lasing threshold , rabi cycle , quantum dot , relaxation (psychology) , oscillation (cell signaling) , condensed matter physics , laser , population , physics , quantum decoherence , quantum dot laser , quantum well , atomic physics , chemistry , quantum , optoelectronics , quantum mechanics , demography , sociology , electron , psychology , social psychology , biochemistry
Abstract A three level scheme based on S–P polaron intersublevel transitions in n‐doped InAs/GaAs self‐assembled quantum dots is proposed to obtain laser effect around 25 µm wavelength under optical pumping. Temperature dependence of the optical gain is theoretically analysed. Lasing effect is expected up to 300 K. To probe the T 2 decoherence time, one of the key parameter driving the laser performances, an optical Rabi oscillation experiment is performed on the pumping transition. Transmission variation is measured as a function of the pump pulse area and modelled by 2‐level optical Bloch equations considering inhomogeneous contributions. We show that the non‐monotonous population dependence and damping of the oscillation is only compatible with a T 2 ∼ 5 ps dephasing time, one order of magnitude longer than in quantum wells and one order of magnitude shorter than the 45 ps relaxation time of the S–P transition, demonstrating a non relaxation‐limited decoherence for the transition. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)