We investigate theoretically the spatial dependence of the linear absorption spectra of single and coupled semiconductor quantum dots, where the strong three-dimensional quantum confinement leads to an overall enhancement of Coulomb interaction and, in turn, to a pronounced renormalization of the excitonic properties. We show that—because of such Coulomb correlations and the spatial interference of the exciton wave functions—unexpected spectral features appear whose intensity depends on spatial resolution in a highly nonmonotonic way when the spatial resolution is comparable with the excitonic Bohr radius. We finally discuss how the optical near-field properties of double quantum dots are affected by their coupling.

The evolution of photoluminescence (PL) spectra of single GaAs/AlGaAs quantum dots (QD) is studied as a function of laser excitation power and temperature. At very low powers, where multi‐exciton occupation of the QD can be excluded, an unexpected and pronounced spectral evolution is observed (large energy shifts and appearance of multiple emission lines). A similar evolution is observed at low excitation powers with increasing temperature. A model, taking into account the influence of the shallow, residual impurities in the environment of each QD, explains the observed spectral evolutions in terms of photo‐depletion of the QD and hopping of impurity‐bound carriers back into the QD. Theoretical calculations of the PL due to Nelectrons + 1 hole (Ne + 1h) QD states allow us to attribute the ≈︂2 meV spaced lines in the experimental spectra to the different charge states Ne + 1h, (N — 1) e + 1h, … of the QD.