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Abstract: We have investigated the ultrafast carrier dynamics in Molecular Beam Epitaxy (MBE)-grown InAs/InGaAs/GaAs quantum dots emitting at 1.3 μm by means of time resolved photoluminescence upconversion measurements with a time resolution of about 200 fs. The detection energies scan the spectral region from the energy of the quantum dot excitonic transition up to the barrier layer absorption edge. We found, under high excitation intensity, that the intrinsic electronic states are populated mainly by carriers directly captured from the barrier. [Copyright &y& Elsevier]

In-plane absorption measurements were performed at room temperature by means of a waveguide transmission setup on a Stranski–Krastanov InAs dots-in-a-well system emitting at 1.3 μm embedded in a p-i-n structure. The polarization dependence of quantum dot (QD) absorption was exploited to resolve its discrete and continuous spectral components and study them separately under reverse bias application. The quantum confined Stark effect observed in the discrete spectral component gave evidence of an upward built-in QD dipole of about 9.5×10-29 C m. The continuous component was found to originate from electronic transitions involving a QD state and a quantum well state. [ABSTRACT FROM AUTHOR]

The authors have performed time resolved photoluminescence measurements by upconversion technique on InAs quantum dots embedded in an InGaAs/GaAs quantum well emitting at 1.3 μm at room temperature. A detailed analysis of the photoluminescence transients as a function of the excitation density and for different detection energies between the quantum dot transitions and the GaAs absorption edge shows that the intradot relaxation is slower than the direct carrier capture from the barrier states through a continuum background relaxation. [ABSTRACT FROM AUTHOR]