Document Type


Creative Commons License

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


Physical Sciences and Mathematics

Publication Details

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 E.A. Viktorov et al., Appl. Phys. Lett. 100, 241108 (2012) and may be found at

The authors would like to thank Bryan Kelleher for proof reading the manuscript. This study has been supported by Science Foundation Ireland (SFI) under contract number 07/IN.1/I929, the Irish Research Council for Science, Engineering and Technology (IRCSET), the Tyndall National Access Programme and the Irish Higher Education Authority under the PRTLI program. The work by E. Viktorov and T. Erneux was supported by the Fond National de la Recherche Scientifique (Belgium). The research by T. Erneux was also supported by the Air Force Office of Scientific Research (AFOSR) Grant FA8655-09-1-3068.


The nonlinear two stage recovery of quantum dot based reverse-biased waveguide absorbers is investigated experimentally and analytically as a function of the initial ground state occupation probability of the dot. The latter is controlled experimentally by the pump pulse power. The slow stage of the recovery is exponential and its basic timescale is independent of pump power. The fast stage of the recovery is a logistic function which we analyze in detail. The relative strength of slow to fast components is highlighted and the importance of higher order absorption processes at the highest pump level is demonstrated.