Local absorption spectra of single and coupled semiconductor quantum dots

We study theoretically the local absorption spectra of single and double se miconductor quantum dots (QDs). in the linear regime. The three-dimensional confinement leads to an enhancement of the Coulomb correlations, while the spectra depend crucially on the size of the 'local' probe. We show that be cause of such Coulomb correlations the intensity of certain optical peaks a s a function of the resolution can exhibit an unexpected non-monotonic beha vior for spatial resolutions comparable with the excitonic Bohr radius. We finally discuss the optical near-field properties of coupled QDs for differ ent coupling strengths. (C) 2001 Elsevier Science B.V. All rights reserved.