Ultrafast carrier dynamics of resonantly excited 1.3-μm InAs/GaAs self-assembled quantum dots

We report the carrier dynamics of 1.3-μm InAs quantum dots (QDs), following resonant excitation in the lowest energy state of QDs. The strong temperature dependence of the escape rates of the carriers leaving the ground state shows the presence of efficient multiphonon processes, involving both acoustic and optical phonons. The very fast activation of electrons to the first excited state implies that, in these QDs, the phonon bottleneck is not observable at room temperature even at low carrier densities where the dynamics is independent of excitation level.