Anomalous Decay of Photon Echo in a Quantum Dot Ensemble in the Strong Excitation Regime

摘要

We investigated the coherent dynamics of exciton ground-state transitions in an 150-layer-stacked straincompensated InAs quantum dot ensemble using photon echo (PE) technique in the strong excitation regime. The time delay dependence of PE signal intensity shows a drastic change depending on the excitation intensity and the aperture position placed in front of a detector. Our results suggest that the excitation-intensity-dependent spatial distribution of PE signal intensity plays an important role in observing PE signal decay in the strong excitation regime.