Optical properties of a quantum-dot cascade structure

We report on our theoretical studies of the luminescence spectra of a quantum cascade laser where the quantum wells in the active regions are replaced by parabolic quantum dots. We analyze the influence of shape and size of the dots on the luminescence spectra. The emission spectra have interaction-induced blueshift which increases almost linearly with increasing electron number. The blueshift is smaller for larger and non-circular dots. For large dots, shape of the emission line has weak dependence on the shape of quantum dots. (C) 2002 Elsevier Science B.V. All rights reserved.