Size and shape effects in electromagnetic response of quantum dots and quantum dot arrays

Size and shape effects in electromagnetic response of quantum dots (QDs) su ch as depolarization shift of the exciton resonance and fine structure of t he gain band are considered on the basis of a unified concept of light conf inement. We show that at sufficiently large oscillator strength of the tran sition, QD behaves itself as a microcavity and excitation of cavity eigenmo des becomes possible, indicating induced magnetism of QDs. Exciton radiativ e lifetime in spherical QD has been evaluated. A phenomenological effective medium theory of electromagnetic response properties of regular ensembles of QDs has been elaborated. We propose that the effect of light confinement should be properly addressed to optimize the design of optoelectronic devi ces involving QDs. (C) 2001 Elsevier Science B.V. All rights reserved.