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Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.


Physical Sciences and Mathematics

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This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in T. Piwonski et al., Appl. Phys. Lett. 97, 121103 (2010) and may be found at

This study has been supported by Science Foundation Ireland (SFI) under the Contract No. SFI 07/IN.1/I929, the INSPIRE Programme, funded by the Irish Government’s Programme for Research in Third Level Institutions, Cycle 4, National Development Plan 2007–2013, and the Institute of Technology Ireland’s Strand I Programme and the Tyndall National Access Program. The authors in Bruxelles acknowledge support of the Fonds National de la Recherche Scientifique (Belgium).


Two-color pump-probe measurements are used to study the carrier dynamics of InAs/GaAs quantum dots in a waveguide structure under reverse bias conditions. For the case of initially populating the ground state (GS), we find relaxation dynamics that include both absorptive and bleaching components in the excited state (ES) wavelength range. We reproduce the main features of this induced absorption dynamics using a simple model with an additional term for induced absorption at the ES due to carriers injected at the GS. The induced absorption dynamics includes multiple recovery timescales which can be attributed to phonon-assisted processes of GS/ES interaction.